Will doing it the opposite way work too? The top of the screen is imovable but the bottom I can move back.

Joe
No, I don't think so. Basic geometry seems to indicate that this will just make the 'keystoning' worse. You want to bring the top of the screen closer to the projector (by tilting the projector, you've moved the top of the lense further away from the screen than the bottom of the lense).

Mr. Wiggles - How do you think tilting the top of a screen forwards impacts screens like Dalite High Power? It would seem to me to increase the viewing angle, and thus lowering the gain. Or is my basic geometry failing me?

Hyrax:
Why would moving the bottom of the screen further away be different than moving the top of the screen closer? What am I missing here?

Hyrax:
Why would moving the bottom of the screen further away be different than moving the top of the screen closer? What am I missing here?
You're not missing anything. What Mr. Wiggles is saying is START by getting the bottom of the screen set up first, then move the top. If you can only move the bottom, its going to be more difficult to set up, but it will still work, as long as the top is closer to the projector than the bottom.

DISCLAIMER: I do not support such a solution for a specific projector, but only if no projector will fit your room design. If you must have 1080p, look into the Sony Ruby (which is already on the market), or wait for the 1080p Sharp / Infocus / Knoll products that should be out around the same time as the Optoma.

Hyrax:
Why would moving the bottom of the screen further away be different than moving the top of the screen closer? What am I missing here?
Sorry ... You're right ... I dyslexic-ized what you were saying. Somehow I got a completely different picture in my mind than what you wanted to do. What you're proposing should work- tilting the PJ upwards and moving the bottom of the screen backwards. It may not be that hard either. Fit the image to the top of thescreen, move the botom of the screen back, and you're there you are.

The Sony BD player is NOT going to support HDMI 1.3. Sorry.

It doesn't matter if the bit depth supported is higher. Neither the source or the display can support it. The panel drivers on these projectors are probably 8 to 10 bits tops and the source software is 8 bit for both HD DVD and BD. While HDMI 1.3 does provide a lot of room to grow, it is only that.

The PS3 was previously announced to support HDMI 1.3 at its November 2006 release while the Sony standalone BD player would not. However, Sony has very recently slipped the release of their BD player from the planned early Aug. date to October. Although there has been no indication that any enhancements will added with the delayed introduction, but who knows, just maybe HDMI 1.3 will be included (especially if the new HDMI interface chip is a direct pin-for-pin replacement) ----- just speculation on my part -----


Ron Jones

I see that the spec is 'officially" anounced, and that the BluRay player from Sony will be sporting it so....

I hope that it is not too late to make the HD81 and the Genum VXP with HDMI 1.3?


New HDMI 1.3 capabilities include:

Higher speed:
• HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high-definition display devices, such as higher resolutions, deep color and high frame rates. In addition, built into the HDMI 1.3 specification is the technical foundation that will let future versions of HDMI reach significantly higher speeds.

Deep color:
• HDMI 1.3 supports 30-bit, 36-bit and 48-bit (RGB or YCbCr) color depths, up from the 24-bit depths in previous versions of the HDMI specification.
• Lets HDTVs and other displays go from millions of colors to billions of colors.
• Eliminates on-screen color banding, for smooth tonal transitions and subtle gradations between colors.
• Enables increased contrast ratio.
• Can represent many times more shades of gray between black and white. At 30-bit pixel depth, four times more shades of gray would be the minimum, and the typical improvement would be eight times or more.

Broader color space:
• HDMI 1.3 removes virtually all limits on color selection.
• Next-generation “xvYCC” color space supports 1.8 times as many colors as existing HDTV signals.
• Lets HDTVs display colors more accurately.
• Enables displays with more natural and vivid colors.

None of which will matter for any Hi-Def content for the likely life of this projector.

Unless you are planning some specialized computer usage for your display, I would not hold my breath (or purchasing $$$) for any HDMI 1.3 display.

None of which will matter for any Hi-Def content for the likely life of this projector.

Unless you are planning some specialized computer usage for your display, I would not hold my breath (or purchasing $$$) for any HDMI 1.3 display.

Steve, I'm not sure what you mean by this? I am just thinking about HDMI 1.3 and the possible impriovements that it can (may) bring to the market.

Any HD PJ I get will be used primarily for HDTV and HD (BD or HDVDV) movie viewing, now having said this the HD movie viewing may be in form of a HTPC connected to the PJ as this is the way I currently view regular DVD's.

Sounds like you are advocating the HDMI 1.3 either isn't worth the wait or is a long way away?

Steve, I'm not sure what you mean by this? I am just thinking about HDMI 1.3 and the possible impriovements that it can (may) bring to the market.

Any HD PJ I get will be used primarily for HDTV and HD (BD or HDVDV) movie viewing, now having said this the HD movie viewing may be in form of a HTPC connected to the PJ as this is the way I currently view regular DVD's.

Sounds like you are advocating the HDMI 1.3 either isn't worth the wait or is a long way away?
Boy, this thread loves to go into HDMI 1.3 discussions. About 5 pages ago, I started a thread for HDMI discussions.

http://www.avsforum.com/avs-vb/showthread.php?t=688325

The importance or irrelevance of HDMI 1.3 effects all displays. Even if the HD81 wanted to support 1.3, I don't think it could. I don't think the chips are out yet. If you know differently put it in the HDMI 1.3 thread.

I also started another thread with 24 bit RGB images designed to test the limitations of that very common format. (I think the limitations are very small but you can be the judge)

http://www.avsforum.com/avs-vb/showthread.php?t=691843

I think you guys are basically repeating a discussion we had earlier in this thread. And it really isn't an HD81 issue; you could get into a long-winded discussion about HDMI 1.3 on any thread at AVS if you wanted to.

-Mr. Wigggles

For joy for joy, end of this month a few weeks away 15 or so will hit the Milpitas Factory. I'm in for testing one, my friend is testing one right now. Asked about the auto-iris and yes it's on board and is working well. Only a matter days now :)

milpitas.... will they have any on display there that the general public can see?

Most likely, in that large theater room they have. Wonder who the other lucky users will be? The trickle has started, end of July not too bad of a wait. I wouldn't expect the main load until end of August but there should be some more pre-shipments I'll bet.

For joy for joy, end of this month a few weeks away 15 or so will hit the Milpitas Factory. I'm in for testing one, my friend is testing one right now. Asked about the auto-iris and yes it's on board and is working well. Only a matter days now :)

Will there also a manual option for the iris?

miller,

There are many options for the iris. Most of them are manual (i.e. fixed).

-Mr. Wigggles

Last we talked the Iris has 17 stops. Real glad they added the auto feature also. They'll be the first DLP/auto iris. Now others will have to follow, hope they have fun trying to implement it. :)

Last we talked the Iris has 17 stops. Real glad they added the auto feature also. They'll be the first DLP/auto iris. Now others will have to follow, hope they have fun trying to implement it. :)

It remains to be seen whether the iris is worth it. If the auto iris introduces artifacts such as brightness compression (and Ruby's does) then one would have to weigh the options to decide if it's right for them.

Not that its bad by any stretch of the imagination; I guess I'm just saying that it needs to be carefully weighed among all factors.

Best,

Engineers do think it's gimmicky though Tzungilin did like what the demo did at Infocomm. Good sales ploy for sure. :)

I know I'll have fun testing the 0 and 100IRE for contrast readings. "Is it real or is it Memorex" ;) People were asking for different stop levels for the Auto feature, that might help keep down the compression. I don't know how fancy they're getting on this first unit.

Hi Tom,

Is it definite that the auto iris is going to be in the HD81 as well as the 17 position manual option? I was under the impression the auto wasn't going to be in this particular model but maybe the later one. If it is included, is the MRP still $9999 (with a street of around $6000).

Gary

To me, the manual iris is very worthwhile (if I understand how it works): one can open it up during the daytime, to get a brighter pic and when super contrast is not so imp, and then close it down at night-time when the room is dark for movies, etc. Sounds like it has the advantages of the 'light cannon' for daytime viewing, and the high constrast for 'critical' viewing (if I'm getting the videophile lingo correct).

Absolutely Gary, it's in the 15 coming in a couple of weeks.The 17stepped manual control will be very useful. Remember the larger 1" chip will give off more brightness plus the 300watt bulb, closing down an Iris on that should make for excellent real time contrast/ansi contrast. With the auto on I'll try to find some compression or see if I can notice brightness changes, who knows it may work great.

Price hasn't changed.

That's great news Tom, thanks for the feedback. :)

Looking forward to this more and more.

Gary

Tom, shoot me an email when you get your HD81 up and running - I've got a bottle of wine ready to bring over, and would love to be a second set of eyes to report on this new machine here at AVS!! I might even have a nice Cuban cigar around here somewhere..... ;)

Boy, this thread loves to go into HDMI 1.3 discussions. About 5 pages ago, I started a thread for HDMI discussions.

http://www.avsforum.com/avs-vb/showthread.php?t=688325

The importance or irrelevance of HDMI 1.3 effects all displays. Even if the HD81 wanted to support 1.3, I don't think it could. I don't think the chips are out yet. If you know differently put it in the HDMI 1.3 thread.

I also started another thread with 24 bit RGB images designed to test the limitations of that very common format. (I think the limitations are very small but you can be the judge)

http://www.avsforum.com/avs-vb/showthread.php?t=691843

I think you guys are basically repeating a discussion we had earlier in this thread. And it really isn't an HD81 issue; you could get into a long-winded discussion about HDMI 1.3 on any thread at AVS if you wanted to.

-Mr. Wigggles

Thanks for the links, as you say this seems to be a long talked about subject, I'll start reading... ;)

I just hate to jump too soon and get stuck because of a connectivity specification!

Tom, shoot me an email when you get your HD81 up and running - I've got a bottle of wine ready to bring over, and would love to be a second set of eyes to report on this new machine here at AVS!! I might even have a nice Cuban cigar around here somewhere..... ;)


Sure thing, great times ahead 1080p and auto iris. I forgot they even throw in a Gennum scaler box. How can the do it? :)

Absolutely Gary, it's in the 15 coming in a couple of weeks.The 17stepped manual control will be very useful. Remember the larger 1" chip will give off more brightness plus the 300watt bulb, closing down an Iris on that should make for excellent real time contrast/ansi contrast. With the auto on I'll try to find some compression or see if I can notice brightness changes, who knows it may work great.

Price hasn't changed.

All real good information Tom, especially the one about the price! :D

Don't say too much about the Scaler, we (at least a lot of us) want it too! I think that it is a great item to be packaged with the HD81, cleans up a lot of connectivity issues for me.

Nice to hear the real machines are out there being tested by the 'nearly public', real world impressions away from a trade show are usually much more interesting to read about.

I hope they will be ready to supply the pent up demand, it would seem that there are a good number of people waiting for this particular unit.

Keep up the good work!

I believe Optoma UK have a couple of preproduction models on test at the moment too, so it's looking good for Europe as well. Over here we're hoping the pricing compares as favourably as it does in the US. It's not unusual to see a straight dollars to pounds price structure (I.e $6000 = £6000), but in the past Optomas prices have been closer to the exchange rate plus local tax, which is good news indeed if that's to be the case.

Gary

Steve, I'm not sure what you mean by this? I am just thinking about HDMI 1.3 and the possible impriovements that it can (may) bring to the market.

Any HD PJ I get will be used primarily for HDTV and HD (BD or HDVDV) movie viewing, now having said this the HD movie viewing may be in form of a HTPC connected to the PJ as this is the way I currently view regular DVD's.

Sounds like you are advocating the HDMI 1.3 either isn't worth the wait or is a long way away?

In deference to Wigggles, I'll keep this brief, and if you have more Q's, we can discuss in his other thread...

The bottom line is that none of the video formats (disc or broadcast) support the increased bit depth (and it's already in the specs, so won't be changing soon), 1.1 already supports 1080p24 (and p30), and can pass 8 channels of digital PCM bitstream (there's no real reason to need audio decoding in the AVR). Hence 1.3 brings nothing useful to the video table.

I've searched around on the thread to see if anyone else has brought this up regarding offset. Can't find it so...

CH has been mentioned several times in this thread. Has anyone discussed the vertical offset inherent to the Panamorph lenses helping negate some of the HD81 offset issue? A flip of the Panamorph, depending on your lens height, might put you back in the game. Anyone played with the math to see?

I've searched around on the thread to see if anyone else has brought this up regarding offset. Can't find it so...

CH has been mentioned several times in this thread. Has anyone discussed the vertical offset inherent to the Panamorph lenses helping negate some of the HD81 offset issue? A flip of the Panamorph, depending on your lens height, might put you back in the game. Anyone played with the math to see?

For those of us who are a little slow, or mathematically challenged can someone please expound on this idea?

(my degree is in statistics so if anyone needs a lie told with real numbers I can help)

Thanks

Joe

Pardon me for posting without experimenting a bit. I do a constant height 2.35 system using a Panamorph U-120. Who could ring in on this is Shawn from Panamorph to give us a percentage of the vertical shift that the lens causes. In reality, it would just take some experimentation. Let's say you don't have the vertical room above the screen to reach the fixed offset of the HD81. It seems if you went CH with the Panamorph you could decide whether the standard mount orientation worked or flip the Panamorph to get the image vertically roughed in, then manipulate the tilt of the lens (which tilts the image up and down, but skews geometry) and the tilt of the projector to achieve the right image height and optically correct geometry. This would be best done with the anamorphic geometry pattern on DVE. It is what I did in my HT. Your scaler plays a role, too. But I think all these would work to provide a working solution to a lot of rooms.

Theory only. Any Panamorph owners/CH guys out there with any ideas?

Cam Man
Check out this thread
http://www.avsforum.com/avs-vb/showthread.php?t=695939
I asked Shawn about the U80 and shift. He replied that, all other things being equal, the 2.35:1 image would be centered, top to bottom, on the 1.78:1 screen. So it seems to me that would be considered no shift. Also I think he said if you do shift it (which you can) some keystoning would be involved to correct the image. I don't know if that answers you question.

The most upward shifting I'd recommend is to the top of the 16:9 frame anyway, and this is with the Panamorph inverted. It would still create a bit of keystoning though, and if you can accept a bit of keystoning then you could just tilt the projector upward to compensation for offset issues or, as some have noted, tilt the screen forward. So unfortunately I don't think the Panamorph would be considered a solution for the offset issue.

Hmm. Thanks for ringing in on this Shawn. Take a look at this pdf (http://www.panamorph.com/Acrobat/ProductGuide.pdf) from the Panamorph site. Notice the drawing on the top right of the page that shows the projector mounted level, projector lens offset directing the image downward, and the Panamorph continues to send the image downward rather than straight out of the Panamorph (as one with limited knowledge of optics like myself would expect). If the Panamorph is inverted, the image is no longer aimed further downward. The third sentence in the text at the top of the page even recommends this as an option.

You can see why this tempts me. Seems like it is worth experimenting with.

Man, it seems forever! :(

I want to read a test about this machine!!

Guitarman, can you help us please.....?? :)

You could read about the Scaler that will come with it. Optoma put the manual up on their website under HD7300.

Next week or the week after for the HD81 review.

You could read about the Scaler that will come with it. Optoma put the manual up on their website under HD7300.

Next week or the week after for the HD81 review.

Tom, Can you confirm that it IS the same scaler?

(edit: found my answer. thanks)

Joe

They only have one, that's it. Plus seems there's a newer Gennum chip a 51 vs at 50, the scaler will have the 51.

They only have one, that's it. Plus seems there's a newer Gennum chip a 51 vs at 50, the scaler will have the 51.

Hmmm, that's a little disconcerting. That means that the unit is not as firmware upgradeable as I expected.

Also, I think I am going to go with the 7300 so I will seee if I can make sure to get the 51 vs the 50.

Thanks

Joe

Image Shift Adjustment on page 35...

up to 100 pixels in each direction

Kinda like a 9% offset adjustment? :D

Also an interesting editing miss on page 43 para. 5 ;)

Dana: I don't understand this.

And a contradiction on the number of 12 volt triggers? On page 51 listed as 'one' and in the specs on page 54 it lists 'two programmable 12v triggers'

I know that this was confirmed in other posts, and I could have missed this in the manual, but there is no mention of 1080p pass through.

Not that I have experience with a lot of scalers (none :rolleyes: ) but his unit seems to cover most if not all bases for image manipulation and switching!

You could read about the Scaler that will come with it. Optoma put the manual up on their website under HD7300.

Next week or the week after for the HD81 review.

OK Tom, now that the HD3000 manual is out of the way what else ya got? :)

Page 53 of the user guide says you can upgrade the firmware and provides the steps.
Is this not correct?

No machine yet, off to Vegas for five days maybe they'll have it when I get back. The waiting's a killer isn't it. :)

Guitarman,

If you don't mind my asking, along with your assessment could you get a qualitative assessment of the HD81's noise level, rainbow effects, & light leakage? Plus, do they allow you to take pictures?

Thank you, sir.

Duke Danont

Further, on the HD3000 processor's manual on Optoma homepage, page 33 mentions something about a 2.35 stretch with "Format 3" to eliminate the black bars. This would then make the Panamorph lens not necessary, correct?

Duke Danont

Just an FYI, there is another thread over in the video sources/scaler section with about 3 pages of Q&A. I learned a ton but it just makes the wait for the 81 review that much more difficult!!!

Did anyone find out what the VGA max reslolution will be on the HD81 for computer monitoring?

Further, on the HD3000 processor's manual on Optoma homepage, page 33 mentions something about a 2.35 stretch with "Format 3" to eliminate the black bars. This would then make the Panamorph lens not necessary, correct?

Duke Danont

Just the opposite - that's the vertical stretch you need to make an anamorphic lens work correctly.

Quote:
Originally Posted by ddanont
Further, on the HD3000 processor's manual on Optoma homepage, page 33 mentions something about a 2.35 stretch with "Format 3" to eliminate the black bars. This would then make the Panamorph lens not necessary, correct?

Duke Danont


Just the opposite - that's the vertical stretch you need to make an anamorphic lens work correctly.

Ahhhhh, yes, thank you sir. That makes more sense.

Did anyone find out what the VGA max reslolution will be on the HD81 for computer monitoring?

Since you asked about VGA resolutions I assume you are referring to analog signals... please excuse the format it is from page 57 of the manual.


Computer Compatibility (Analog)
Compatibility Resolution V-Sync [Hz] H-Sync [KHz]
VGA 640x480 60 31.5
640x480 72 37.9
640x480 75 37.5
US TEXT 720x400 70 31.5
SVGA 800x600 56 35.2
800x600 60 37.9
800x600 72 48.1
800x600 75 46.9
XGA 1024x768 60 48.4
1024x768 70 56.5
1024x768 75 60.0
Wide 848x480 60 31.1
1280x720 60 45
1280x768 60 48
1280x768 75 60.1
1366x768 60 48.1

Having said this, it should be no problem to connect it via the digital connection and set the PC to 1920x1080 and have a 'pixel perfect' display of your computer's screen!

Having said this, it should be no problem to connect it via the digital connection and set the PC to 1920x1080 and have a 'pixel perfect' display of your computer's screen!

Unfortunately, the manual for the scaler suggests the maximum resolution of the HDMI inputs is 1080i. I hope this is not the case.

Unfortunately, the manual for the scaler suggests the maximum resolution of the HDMI inputs is 1080i. I hope this is not the case.

I don't see the problem, the output can be 1080p :)

I don't see the problem, the output can be 1080p :)

I think the question is "Can you send a 1080p signal to the processor."

Joe

I think the question is "Can you send a 1080p signal to the processor."

Joe

So, does anyone have an answer?

I understand that there was a demo of the HD81 in Hong Kong today (unless I'm mistaken but I don't think my Chinese is that bad). Did any forum member get to attend? If so, how does it look? I'm sure everyone is dying for a review.

I should've bought my copy of AV Bi-Weekly earlier. Then I could've signed up.

I think the question is "Can you send a 1080p signal to the processor."

Joe

You can send a 1080p signal but then the Gennum's deinterlacing is bypassed. That would be fine if your device can deinterlace better than the Gennum. I'll ask more about sending 1080p DVD player signals to the processor late next week.

You can send a 1080p signal but then the Gennum's deinterlacing is bypassed. That would be fine if your device can deinterlace better than the Gennum. I'll ask more about sending 1080p DVD player signals to the processor late next week.

But all the other filters (gamma, sharpening, denoise,...) continue to work with a 1080p signal, right?

You can send a 1080p signal but then the Gennum's deinterlacing is bypassed. That would be fine if your device can deinterlace better than the Gennum. I'll ask more about sending 1080p DVD player signals to the processor late next week.

Yes, this is the question, bypassing the deinterlacing would be great, but lets hope that all of the signal manipulation made available by the scaler is available as queried by 'The Lion'

For sure, they work when sending other progressive signals. All are functional with any type of signal.

If you're an image tweaker you'll love the (gamma, sharpening, BW ehancement and the many others. You can fuss around for hours with that stuff, I did.

For sure, they work when sending other progressive signals. All are functional with any type of signal.

If you're an image tweaker you'll love the (gamma, sharpening, BW ehancement and the many others. You can fuss around for hours with that stuff, I did.


Thanks Tom, and that makes sense too.

I can't wait to see a HD81 in action! Looking forward to your review...

Tom, do you care to find out if the HD81 is actually using the exact same lense as the EP910 it is based on??? I know the EP910 lense very well because I use this projector at work.

Lense quality has quickly become one of the MOST important and yet sadly overlooked factors when buying a projector - especially one with 1080p resolution. I just saw a 2 hours shootout between a Ruby (with quite good convergence) and the new SIM2 3000 single chip 1080p DLP at my local dealer - the SIM2 had so much chromatic abbreviation that it was actually softer than the 3 chip SXRD Ruby.....

When they start to put lenses like that in EURO 17.000 projectors I wonder what Optoma accomplishes at their price point...

Tom, do you care to find out if the HD81 is actually using the exact same lense as the EP910 it is based on??? I know the EP910 lense very well because I use this projector at work.
I don't know the answer to this, but I'm pretty sure the throw ratios are different between the EP910 and the HD81, so that may suggest that they are different.

How is the quality of the EP910 lens, by the way?

Lense quality has quickly become one of the MOST important and yet sadly overlooked factors when buying a projector - especially one with 1080p resolution.
I couldn't agree more! Lets hope Optoma didn't shortchange us in this regard...


-Dave

I don't know the answer to this, but I'm pretty sure the throw ratios are different between the EP910 and the HD81, so that may suggest that they are different.

How is the quality of the EP910 lens, by the way?


I couldn't agree more! Lets hope Optoma didn't shortchange us in this regard...


-Dave

Dave, the different throw ratios are because of the different sized DLP chips used - 1080p is 0.95' - in the same lightpath.

The lens in the EP910 is very good but not outstanding. Sharp with little chromatic abbreviation. IMO the lack of lense shift will actually help Optoma alot in accomplishing a tightly focused image. Lense Shift is no free lunch - it certainly degrades the image. HD81's biggest drawback might turn out to be its greatest advantage in PQ!

You can send a 1080p signal but then the Gennum's deinterlacing is bypassed. That would be fine if your device can deinterlace better than the Gennum. I'll ask more about sending 1080p DVD player signals to the processor late next week.

The true usefulness in permitting a 1080p input signal would not be from using a DVD player with 1080p output, since the Gennum chip would do a great job of deinterlacing the 480i signal. The usefulness would be in connecting a computer with 1080p output or an HD DVD or Blu-ray player with 1080p output. Eventually, we will have such high-definition players that will be able to create a 1080p/24 or 1080p/60 picture directly from the video data, which is essentially stored as 1080p/24.

Steve, after reading the scalers manual I'm quite excited about the picture tweaking possibilties it provides - especially the prospect of using the very flexible Sharpness filter (simular approach as "Limited Sharpen" used with ffdshow/HTPCs) on a 1080p/24 HD-DVD/BluRay signal.

What puzzles me though is why the manual states full a 10 bit video processing path WITH THE EXCEPTION OF HDMI (In/Out) signals???

Tom, have you had a chance yet to take a look at lumens after D65 calibration? I can't find any mention on lumens in quite a while.

Tzungilin measured 900 lumens after he tuned the HD81 to D65k.

Tom, do you care to find out if the HD81 is actually using the exact same lense as the EP910 it is based on??? I know the EP910 lense very well because I use this projector at work.

Lense quality has quickly become one of the MOST important and yet sadly overlooked factors when buying a projector - especially one with 1080p resolution. I just saw a 2 hours shootout between a Ruby (with quite good convergence) and the new SIM2 3000 single chip 1080p DLP at my local dealer - the SIM2 had so much chromatic abbreviation that it was actually softer than the 3 chip SXRD Ruby.....

When they start to put lenses like that in EURO 17.000 projectors I wonder what Optoma accomplishes at their price point...

I would not be surprised if that effect was caused by mounting the PJ too high and then compensating by using keystoning, and/or misadjusted lens shift or focus.

I see this alot and in some very expensive HTs. Two weeks ago I calibrated a Ruby. The lense shift was misadjusted so that the picture was too high. The PJ was then aimed down and keystoning applied to square up the image.

You can't take it for granted that a dealer has properly installed and calibrated a PJ, unfortunately.

Glenn

Tzungilin measured 900 lumens after he tuned the HD81 to D65k.

How? With an iris opened up all the way and resulting in 1000:1 on off CR? Outside of a Ruby style DI, I doubt the new single chip DLPs will be able to be bright and have a high CR at the same time.

If it could, that would be a significant and welcome technological leap.

Glenn



Glenn

How? With an iris opened up all the way and resulting in 1000:1 on off CR? Outside of a Ruby style DI, I doubt the new single chip DLPs will be able to be bright and have a high CR at the same time. Excellent point.

TZ, we need you to ring in on this, please. If TZ may not respond anymore, we must rely on you, Tom.

You can send a 1080p signal but then the Gennum's deinterlacing is bypassed. That would be fine if your device can deinterlace better than the Gennum. I'll ask more about sending 1080p DVD player signals to the processor late next week.

And if the material is stored 1080p and output 1080p; the Gennum deinterlacing buys you nothing.

That's not to say that it doesn't have other desirable qualities such as NR, Sharpness and the possibility of custom color parms and gammas per source if needed.

How? With an iris opened up all the way and resulting in 1000:1 on off CR?
He measured it in the demo unit which was without an iris- I believe he mentioned this in the first post in the thread. Also, there was no mention of 1000:1 contrast back then.

I read this in a Hong Kong press site:
http://orisun.com/cgi-bin/orimain/search/orisearch.cgi?search_query=hd-81&start=1&end=10

I don't know how accurate the info is? Spec. of HD-81 state in Chinese as:

Resolution: 1920x1080
Brightness: 1,400 Lumen
Contrast: 6,000:1 (12,000:1 Iris mode)
Gennum box Input:
HDMI x3, Component x2, VGA/BNC x2, S-Video x3, Composite x3
List price: HK$78,000 (Edit)

I read this in a Hong Kong press site:
http://orisun.com/cgi-bin/orimain/search/orisearch.cgi?search_query=hd-81&start=1&end=10

I don't know how accurate the info is? Spec. of HD-81 state in Chinese as:

Resolution: 1920x1080
Brightness: 1,400 Lumen
Contrast: 6,000:1 (12,000:1 Iris mode)
Gennum box Input:
HDMI x3, Component x2, VGA/BNC x2, S-Video x3, Composite x3
List price: HK$7,800

$7,800 Hong Kong dollars is $1,003 USD! Do you mean USD $7,800 or 78,000 HK$?

Sorry, it's HK$78,000!

I'm starting to plan my projector mounting location and was hoping to get some feedback from those of you that are more familiar with Optoma projectors (I've never owned one). The Sony Ruby is known to perform much better (i.e. brighter) being placed as close to the screen as possible. It is quite a difference by the way - you can lose a third of your brightness from one extreme to the other!

Does anybody know if Optoma projectors tend to have similar issues? I'd like to push the projector as far back in the zoom range as possible simply to get it (and associated fan noise) away from my primary seating position.

I'd also really like confirmation on the serial cable between the scaler and the projector. Some press releases seem to indicate that only a "single" cable is required; others (including TzungILin, who should certainly know) mention that both HDMI and serial are required.

-Dave

I don't think this a phenomenon associated with a particular manufacturer. It's a function the specific lens being used in the projector.

I don't think this a phenomenon associated with a particular manufacturer. It's a function the specific lens being used in the projector.Understood. I think the Ruby has a very wide zoom range and that may have something to do with it. The H81 is much narrower (1.8 - 2.2 throw ratio per the first post in this thread) so it is probably less of an issue.

-Dave

In essence, its what is the effective aperture at the point of the zoom you are using. The lens will have a smaller effective F stop (trhat is it will be faster or able to transmit more light at the 1.8 zoom position than it will at the 2.2 position. In the Sony, one goes from 1.41 to 2.4, a very wide zoom range and a big effective F stop difference. Of course a zoom could be built to have a constant maximum aperture accross its zoom range but this would be very expensive. With only a .4 zoom range the fall off at 2.24 vs 1.8 shouldn't be much with the Optima.

Unfortunately, the manual for the scaler suggests the maximum resolution of the HDMI inputs is 1080i. I hope this is not the case.

...and so do I!!... :(

-THTS

I'd also really like confirmation on the serial cable between the scaler and the projector. Some press releases seem to indicate that only a "single" cable is required; others (including TzungILin, who should certainly know) mention that both HDMI and serial are required.
I believe what TzungILin said was all you need is the HDMI cable from the scaler to the projector. If you want to use a specialized remote control, the scaler has a RS232 output (which is a serial type cable) that would also have to be connected to the projector.

Read this on Projector Central: By the way, in case you missed it, Optoma has announced an estimated street price of just $5,999 for the new HD81, which is their first 1080p resolution product. Optoma has traditionally been aggressive in pushing prices on all resolutions down.

I was hopiong that the price point would be around here, but it's nice to see it in writing.

Here's the link: http://www.projectorcentral.com/projector_news071706.htm

If that is the price then you can guarantee I will end up buying the HD81... Especially since with online retailers, the ones that aren't con artists, I can get it for significantly less. If it is the same price as the Ruby or only a little less, I'll probably end up with the Ruby since it is more convenient for me to set up and there is a lot more information and help available online since it has been around for longer.

Here's to hoping that is an accurate estimate on the price.

...and so do I!!... :(

-THTS

I would say that posts 1055-1059 put the question of 1080p to rest...

Considering that this price presumably includes the external Gennum scaler, this is an amazing value.

I would say that posts 1055-1059 put the question of 1080p to rest...
We are talking about 1080p over HDMI. Tom doesn't have the projector, only the scaler, and it doesn't sound like he actually tested it.

Tom has a habbit of stating educated guesses as facts. There's a good chance he's right but until someone actually inputs a 1080p signal over HDMI we won't know.

-Mr. Wigggles

In response to the questions about the lens, I suspect that by not providing lens shift, Optoma should have the ability to provide a decent lens with sharp visuals. Every review of the 7100 has mentioned how sharp the picture is and how good the lens is, and that's at a lower price point. I too hope that the HD81 will have a sharp lens, although I'm still not sold on the value of HD81 over the Ruby and even possibly over the D6 3LCD camp (it will all depend on comparative street pricing at the time of their introduction.)

In response to the questions about the lens, I suspect that by not providing lens shift, Optoma should have the ability to provide a decent lens with sharp visuals.That's interesting. I have always thought of lens shift as just a variable offset. With lens shift the entire lens assembly is literally translated up and down. And focusing/chromatic aberrations are generally thought to get worse the greater the offset is from zero. So, the questions are (a) if the offset is known ahead of time, can the lens be designed to optimise performance for that particular offset ? & (b) would the manufacturer actually do it in any case (given that the primary reason to go with fixed offset is almost certainly cost saving) ?


Brent

We are talking about 1080p over HDMI. Tom doesn't have the projector, only the scaler, and it doesn't sound like he actually tested it.

Tom has a habbit of stating educated guesses as facts. There's a good chance he's right but until someone actually inputs a 1080p signal over HDMI we won't know.

-Mr. Wigggles

Yes you are correct, not officially confirmed... and living up to your moniker regarding "truth" :D

I had contacted Optoma last week to see if I could get a more firm release date and just heard back from them. They say it still isn't official but "right now it looks like it will ship in early September."

I wonder if any will ship before Cedia or if they'll hold them back until a big "official" introduction there.


-Dave

I had contacted Optoma last week to see if I could get a more firm release date and just heard back from them. They say it still isn't official but "right now it looks like it will ship in early September."

I wonder if any will ship before Cedia or if they'll hold them back until a big "official" introduction there.


-Dave

Did you ask what the MSRP would be, or if the more recent estimate is accurate?

Did you ask what the MSRP would be, or if the more recent estimate is accurate?No, I didn't ask about the MSRP. I assume the $5,999 "street price" is accurate since it was in their June 7th press release.

I'm still absolutely blown away by that price, by the way. Considering the scaler itself is worth $1,500 (just compare it to other Gennum-based scalers) that puts the price of the projector at $4,500. That is just mind-bogglingly cheap!

I predict a *huge* price drop on the Marantz 1080p projector post-Cedia to try and move inventory....


-Dave

No, I didn't ask about the MSRP. I assume the $5,999 "street price" is accurate since it was in their June 7th press release.

I'm still absolutely blown away by that price, by the way. Considering the scaler itself is worth $1,500 (just compare it to other Gennum-based scalers) that puts the price of the projector at $4,500. That is just mind-bogglingly cheap!

I predict a *huge* price drop on the Marantz 1080p projector post-Cedia to try and move inventory....


-Dave

Well, I'll be waiting on its release then. :)

How? With an iris opened up all the way and resulting in 1000:1 on off CR? Outside of a Ruby style DI, I doubt the new single chip DLPs will be able to be bright and have a high CR at the same time.

If it could, that would be a significant and welcome technological leap.

Glenn



Glenn

Just got back from Vegas, Glenn that was the CES demo without an Iris. My guess is we might see numbers like 6000.1 using certain spots with the Iris fixed. 15000.1 there abouts using the automatic Iris.

Wing (Optoma's Engineering Mgr) told me they picked the 910 platform because it has a large lens that could handle the larger chip. He said the glass is excellent and comes from the same outfit Nikko Japan where they get the lens for the HD7300.

I haven't had a projector with super sharp optics like the HD7300. The clarity is so good many of the first to see it thought the screen door was more noticable. Well yeah the grid is sharp and clear from corner to corner, it's a good thing. :)

I'll take a good look at the HD81's uniformity, we'll see.

I haven't followed this thread for a while so it might have already been posted, but I understand the lens offset is now 38%. This becomes very problematic for all but the highest ceilings. Can anyone verify this?

I haven't followed this thread for a while so it might have already been posted, but I understand the lens offset is now 38%. This becomes very problematic for all but the highest ceilings. Can anyone verify this?
Where is this information from? That is quite a bombshell if true, given that 27% is already quite a stretch for many people (myself included).

-Dave

Where is this information from? That is quite a bombshell if true, given that 27% is already quite a stretch for many people (myself included).

-Dave

I am guessing that the 3 is a little too close to the 2 on the keypad and the 8 is a little too close to the 7. ;)

Joe

Is there a release date for when this will be sold to the general public yet?
Cheers

Where is this information from? That is quite a bombshell if true, given that 27% is already quite a stretch for many people (myself included).

-Dave
The info (38%, that's 38) comes direct from Optoma via my distributor who made the call in my presence. Delivery is said to be 3rd or 4th week of September. I've had one on order for a customer since March and his theater is now done with no projector and we can't even mount the screen because of the changing offset.

This thread is gargantuan, to be sure, but it doesn't take much effort to find your necessary information. The projector is based on an existing business chassis, and this was done to provide quicker time to market, at the expense of a lack of features some want to see in a more thoroughly original design. The good news, though, is that many specifications are well known, as the following, from THE FIRST POST IN THE THREAD:

TzungILin said,

6. The throw ratio is about 1.8 to 2.2:1 (about), the offset is 27% (of vertical height), sorry that this may not fit everyone's installation.

Hope this helps! :)

This thread is gargantuan, to be sure, but it doesn't take much effort to find your necessary information. The projector is based on an existing business chassis, and this was done to provide quicker time to market, at the expense of a lack of features some want to see in a more thoroughly original design. The good news, though, is that many specifications are well known, as the following, from THE FIRST POST IN THE THREAD:



Hope this helps! :)
I know, but his post was in January. I got my info 3 days ago. Maybe he can chime in to give us the current correct percentage. Don't get me wrong, I hope I'm incorrect about this as I was very impressed at CES, and 38% severely limits it's usefulness.

You ordered a pj for a customer six months before it is released? Why?

Ericglo

You ordered a pj for a customer six months before it is released? Why?

Ericglo
Release date was supposed to be May. We just finished the audio and got the screen. It should have been available 2 months ago. We were very impressed with the CES demo, the processor, & the price. Also it was to be the only pure 1080p unit to be available when we needed it. Of course all has now changed, and my decision is revocable.
What would any of you do?

Release date was supposed to be May. We just finished the audio and got the screen. It should have been available 2 months ago. We were very impressed with the CES demo, the processor, & the price. Also it was to be the only pure 1080p unit to be available when we needed it. Of course all has now changed, and my decision is revocable.
What would any of you do?

If you can't use it in the room anywhere reasonable... Perhaps it is time to cancel the order.

I haven't figured out if I can use it yet myself in my space with that percentage and won't have time to do so in the immediate future (at least until it is confirmed as true!). I do have the option of moving it far forward in the room if I need to, within reason. If it doesn't work though, it doesn't work, and I'm not going to f*** up acoustic treatment of my room just to use this projector.

Release date was supposed to be May. We just finished the audio and got the screen. It should have been available 2 months ago. We were very impressed with the CES demo, the processor, & the price. Also it was to be the only pure 1080p unit to be available when we needed it. Of course all has now changed, and my decision is revocable.
What would any of you do?

I believe that I am going to go with the hd7300 and hope that a version 2 of the hd81 will have a shorter throw and less offset. I am also hoping that there would be a pj only upgrade as I would already have the processor.

Time will tell...

Joe

Release date was supposed to be May. We just finished the audio and got the screen. It should have been available 2 months ago. We were very impressed with the CES demo, the processor, & the price. Also it was to be the only pure 1080p unit to be available when we needed it. Of course all has now changed, and my decision is revocable.
What would any of you do?
For a customer, I'd drop in a 720P projector on an adjustable mount, until the one they want comes out. A Knoll 284 comes to mind, because I carry Knoll and because its offset and throw ratio are pretty close to this HD81.

Sidenote: I spoke to Knoll yesterday about their 1080P projector (which will be a rebadged and slighlty modified Infocus unit) and while they are shooting for a September release, I could tell they are struggling to meet that mark. January is more reasonable. Their ace in the hole will be the availability of two lenses - short and long throw.

Decision is made. Faced with uncertain delivery dates for 1080p units, unknown vertical offset of HD81, and not wanting to wait until I go to CEDIA to see what's what, he decides on the 777 and it's best price 3 chipper. Combined with VP30 should be very nice and a real light canon, plus it's pretty.

Decision is made. Faced with uncertain delivery dates for 1080p units, unknown vertical offset of HD81, ...
The offset IS 27%

As stated earlier, the first post is by the actual engineer for the projector. The first post is still 99%, if not 100%, accurate. At 38% the projector would be in past the ceiling in almost every install (not even my screen tilting method would help enough.)

Your distributor is likely mistaken. The geometry of the projector is going to be the same as the Optoma EP910 SXGA projector it is based off of. The SXGA chip is a different shape then the 1080p chip (same diagonal), so it is possible that with the chip in the same positon that the image off of the 1080p chip would be more offset. Hopefully Optoma has corrected for this and until told differently I have to believe the 27% number is still correct. I hate to stereotype but dealers and distributors facts should be taken like most people's rumors. If you hear something surprising from a dealer or distributor, your first reaction should be: "No way."

-Mr. Wigggles

Does anyone have any idea yet, any of the mounts (ones that are variable in length) that will likely fit this model yet? The projector will work in my space and it won't interfere with any of the treatments which will be installed, but I need to find a mount that it will work with which will be able to mount it at 6.45" off of the ceiling.

Thanks

The offset IS 27%

As stated earlier, the first post is by the actual engineer for the projector. The first post is still 99%, if not 100%, accurate. At 38% the projector would be in past the ceiling in almost every install (not even my screen tilting method would help enough.)

Your distributor is likely mistaken. The geometry of the projector is going to be the same as the Optoma EP910 SXGA projector it is based off of. The SXGA chip is a different shape then the 1080p chip (same diagonal), so it is possible that with the chip in the same positon that the image off of the 1080p chip would be more offset. Hopefully Optoma has corrected for this and until told differently I have to believe the 27% number is still correct. I hate to stereotype but dealers and distributors facts should be taken like most people's rumors. If you hear something surprising from a dealer or distributor, your first reaction should be: "No way."

-Mr. Wigggles
My Distributor called Optoma directly, twice to verify because I told him that was wacky, and 38% was verified. Until it actually arrives as a production unit I have to assume that that percentage is a distinct possibility. You even said because the chips are a different shape the offset would be greater if not corrected. Maybe they couldn't correct it without greater delay or expense.

Does anyone have any idea yet, any of the mounts (ones that are variable in length) that will likely fit this model yet? The projector will work in my space and it won't interfere with any of the treatments which will be installed, but I need to find a mount that it will work with which will be able to mount it at 6.45" off of the ceiling.

Thanks
I think the Chief RPA would be ideal , and 6.45" is no problem.

I do not believe that Optoma will introduce the hd81 with an 38% offset. Why make such a powerful machine way below $10k but allmost nobody can install!. That would be madness if you ask me!. The are misleading all of us, including the competition.....i hope! :)

I know, but his post was in January. I got my info 3 days ago. Maybe he can chime in to give us the current correct percentage. Don't get me wrong, I hope I'm incorrect about this as I was very impressed at CES, and 38% severely limits it's usefulness.

There is no need for him to 'chime in to give us the current correct percentage' if he did so in the first post of this thread. I will trust the engineer over some unknown person from Optoma telling your distributor who told you...

Why/how would the spec change that much from a projector they have already shown?

There is no need for him to 'chime in to give us the current correct percentage' if he did so in the first post of this thread. I will trust the engineer over some unknown person from Optoma telling your distributor who told you...

Why/how would the spec change that much from a projector they have already shown?
I hope you're all correct for everyone's sake, including Optoma.

"The SXGA chip is a different shape then the 1080p chip (same diagonal), so it is possible that with the chip in the same positon that the image off of the 1080p chip would be more offset."

If the chips' centers are in the same place, I don't see why the offset would be different.

"The SXGA chip is a different shape then the 1080p chip (same diagonal), so it is possible that with the chip in the same positon that the image off of the 1080p chip would be more offset."

If the chips' centers are in the same place, I don't see why the offset would be different.
Offset is typically done with the following formula*:

%_Offset = distance_to_image_edge_from_lens_height / image_height X 100

So, if you put a projector on the floor with an offset of 27%, with a 5 foot image height, the bottom image edge would rise 1.35 feet off the floor (the floor being roughly the lens position).

Now look at TI's product line-up: http://www.dlp.com/dlp_technology/dlp_technology_products.asp

Notice how the 1080p and the SXGA+ chips appear to have the same package - just the shape of the imager is different? Well, if you took a projector that uses the SXGA chip (i.e. EP910) and simply slapped in an 1080p chip (i.e. HD81), the resulting image would become wider and shorter. Well, the new image being shorter would effectively increase the offset both in terms of physical distance from the floor and in terms of percent because the image is no longer as tall.

How much? I caculate the new offset would be 43.3%**. So IF Optoma mearly took an EP910 and changed out its imager with a 1080p imager, the offset would become 43.3% instantly***. Is that what Optoma did? I doubt it. I think they compensated and the 27% mentioned in the first post is the correct number.

-Mr. Wigggles

*What Tzung calls "27%" is often termed "127%" by other manufacturers.

**Don't ask me how I came up with that number. The calculation would blow your mind! (and showing my work might reveal its innaccuracy as well.)

***I am asuming the EP910 is 27% to begin with but there is no mention of its actual offset in the user's manual just a crude drawing.

How much? I caculate the new offset would be 43.3%**.

**Don't ask me how I came up with that number. The calculation would blow your mind! (and showing my work might reveal its innaccuracy as well.)
:)

< I removed my questions about the 43% after seeing the last assumption >

Okay I see that you assumed 27% to start with for the EP910. So, I can see how you ended up with such a large offset for a 1080p chip with the same setup. I'm not sure why you would assume that 27% is the offset of the EP910 though. I would go the other way and guess that the offset for the EP910 is more likely to be 17%, because that is what would result in the 27% for the 1080p version with no other changes. Unless the drawing gave a strong indication that it was 27%.

--Darin

*What Tzung calls "27%" is often termed "127%" by other manufacturers.I think it would be termed 77%, yielding 0% when the lens is opposite the center of the screen.
***I am asuming the EP910 is 27% to begin with but there is no mention of its actual offset in the user's manual just a crude drawing.The picture indeed suggests 27%, but I think the drawing and all subsequent conclusions are worth nothing, because when I look at the EP747 manual, it contains an additional explicit specification of the offset, and this does not at all scale to the EP747's offset drawing.

... I would go the other way and guess that the offset for the EP910 is more likely to be 17%, because that is what would result in the 27% for the 1080p version with no other changes. Unless the drawing gave a strong indication that it was 27%.

--Darin
My response was basically aimed at Noah who essentially asked: "How can using a different chip with the same light engine give a different offset."

My response was IF the EP910 was 27% AND Optoma simply swapped chips, THEN the HD81 would have a 43.3%* offset.

-Mr. Wigggles

*because you were curious: ((0.95"*3/5*(0.27+0.5))-(0.95"*9/18.36*0.5))/(0.95"*9/18.36) = .442 = 44.2% [I must have had some round-off error the first time I performed it when I got 43.3%.] I hope your cranium is still intact.

I think it would be termed 77%, yielding 0% when the lens is opposite the center of the screen.

Infocus would call it a 127% offset:

http://www.infocus.com/service/howto/guides/install/imageoffset_How_To.pdf

-Mr. Wigggles

Infocus would call it a 127% offset: There must not be logic as long as we have definitions...

"Well, the new image being shorter would effectively increase the offset both in terms of physical distance from the floor and in terms of percent because the image is now longer as tall. "

I see, thanks.

I'm getting an HD81 after next week, I'll give a real time setup configuration once I ceiling mount it. Most likely as stated at 27%. I'll stick with the makers original thoughts, the 16.9 chip will make for a much easier offset 27%.

Damn these CRT's are dim. :) I'm toying with a FP/CRT

And that's in the cone with a HP screen. Blacks and smoothness/softness is nice. :)

Bring on the 1300lumened HD81

Wow Guitarman, my hart goes wild!!

I hope to buy a hd81 myself in the near future when it comes out in the Netherlands, so i will be monitoring this space frequently!! :)

I think the Chief RPA would be ideal , and 6.45" is no problem.

Yes, I'm sure Chief will have a solution for this model and the RPA series are excellent mounts and the only thing I quote in my jobs. They also have a new Elite series that just came out. A simple 1 1/2" threaded NPT pipe that can be had at HD or Lowes is all you need for the 6.45" drop, which can be painted black to match or you can get their stock extension poles for a bit more.

We are dealers for Chief here at AVS, so give us a call when you need one.

Decision is made. Faced with uncertain delivery dates for 1080p units, unknown vertical offset of HD81, and not wanting to wait until I go to CEDIA to see what's what, he decides on the 777 and it's best price 3 chipper. Combined with VP30 should be very nice and a real light canon, plus it's pretty.

Did you know about the Kodak 333 1280x720 3-chip DLP that's virtually the clone of the 777 for thousands less? If not, I'd check it out before you drop some cash on that 777. http://www.avsforum.com/avs-vb/showthread.php?t=690344

Did you know about the Kodak 333 1280x720 3-chip DLP that's virtually the clone of the 777 for thousands less? If not, I'd check it out before you drop some cash on that 777. http://www.avsforum.com/avs-vb/showthread.php?t=690344
The 333 is an old 777 with an HD-2 chip. The current 777 is HD-2+ DC-3, which is 2 generations newer. We don't need the extra lumens of the 333, in fact an ND filter would probably be needed for it. The customer wanted the best established unit at this price point. It's going into a pretty good system with DVDO VP-30; Theta CB III, Compli, Dreadnaught, & Six Shooter; Oracle CD Turntable; Wilson Watt Puppy 8 and Watch System; 2 SVS PB-12 Ultra/2's with QSC DSP EQ. All Synergistic Research Active Shield Cable as well. So far he loves the Audio. Hope the 777 works out as well.

The actual offset of HD81 is 36.2% of the screen height.

Optoma number is measured from the top of the screen so the offset quoted was 136.2%

Actual offset of EP910 is 120%

The formula Mr. Wigggles used has one slight inaccuracy, while both DMD of EP910 and HD81 claimed to be the same 0.95" in diagonal size - HD81 DMD is actually slightly smaller. (actually neither of the two DMDs are exactly 0.95")

My response was basically aimed at Noah who essentially asked: "How can using a different chip with the same light engine give a different offset."

My response was IF the EP910 was 27% AND Optoma simply swapped chips, THEN the HD81 would have a 43.3%* offset.

-Mr. Wigggles

*because you were curious: ((0.95"*3/5*(0.27+0.5))-(0.95"*9/18.36*0.5))/(0.95"*9/18.36) = .442 = 44.2% [I must have had some round-off error the first time I performed it when I got 43.3%.] I hope your cranium is still intact.

Thanks Wing for clarifying that. So with the EP910 at 20% not 27% we have by my equation:

((0.95*3/5*(0.20+0.5))-(0.95*9/18.36*0.5))/(0.95*9/18.36) = .357 = 35.7%

Now, with the 1080p chip being slightly smaller than advertised (let's say 0.944") we have:

((0.95*3/5*(0.20+0.5))-(0.944*9/18.36*0.5))/(0.944*9/18.36) = .362 = 36.2%

Damn, I'm so good it hurts.

But speaking of the Optoma, that offset is going to make installation even more difficult. People with 9 foot ceilings are going to be fine, but things are going to get tricky even for the 8 foot ceiling people. (Or maybe you can just put this projector underneath your couch.)

-Mr. Wigggles

Hey Mr. Wiggles...

Did you get my PM re: Ref Images from a week or so ago?

Best,

The actual offset of HD81 is 36.2% of the screen height.

Optoma number is measured from the top of the screen so the offset quoted was 136.2%

Actual offset of EP910 is 120%

The formula Mr. Wigggles used has one slight inaccuracy, while both DMD of EP910 and HD81 claimed to be the same 0.95" in diagonal size - HD81 DMD is actually slightly smaller. (actually neither of the two DMDs are exactly 0.95")

Thanks for the information, though it is very disappointing.

Thanks for the clarification Mr. Wing!

Now if I want to throw a 135" image, within what distance will the projector have to be mounted?

The actual offset of HD81 is 36.2% of the screen height.

Optoma number is measured from the top of the screen so the offset quoted was 136.2%

Actual offset of EP910 is 120%

The formula Mr. Wigggles used has one slight inaccuracy, while both DMD of EP910 and HD81 claimed to be the same 0.95" in diagonal size - HD81 DMD is actually slightly smaller. (actually neither of the two DMDs are exactly 0.95")

OMG :eek: :confused: :( :mad: :mad: :mad: :mad:

There you have a projector with all the right features, at the right price point and being released at the right time and then Optoma is not able to modify the EP910s lightpath in a way that people (in general with some very few exceptions) can actually USE this projector?!? Please forgive my harsh words but I was impatiently waiting for this projector since its announcement - was planning my whole home theater around it - was getting more and more excited about its features (dynamic iris, 12 step manual iris, 300W lamp,...) - I even forced myself to accept its advertised 27% fixed-offset after a while - and now everything for me and all the others looking forward to using this projector on a fairly large screen (which btw is the whole point of buying a bright 1080p projector anyway) in anything smaller/lower than a warehouse is OVER...

Thanks for the clarification Mr. Wing!

Now if I want to throw a 135" image, within what distance will the projector have to be mounted?

135" image with the HD81... you are joking, right??? You would need like 9 feet ceilings and a 19 feet long room...at the very least...with your screen touching your floor and the HD81 right at your back wall. Time for a new plan I guess.

So is my math correct: On a 92 diag screen in the 16x9 config (45 inches tall), the projector would need to be 17 inches above the top of the screen or 17 inches below the bottom of the screen?

nathan:

No, it would need to be 16.29" above or below the screen.

The offset is 36.2% of screen height, and 36.2% of 45" is 16.29".

Best,

OMG :eek: :confused: :( :mad: :mad: :mad: :mad:

There you have a projector with all the right features, at the right price point and being released at the right time and then Optoma is not able to modify the EP910s lightpath in a way that people (in general with some very few exceptions) can actually USE this projector?!? Please forgive my harsh words but I was impatiently waiting for this projector since its announcement - was planning my whole home theater around it - was getting more and more excited about its features (dynamic iris, 12 step manual iris, 300W lamp,...) - I even forced myself to accept its advertised 27% fixed-offset after a while - and now everything for me and all the others looking forward to using this projector on a fairly large screen (which btw is the whole point of buying a bright 1080p projector anyway) in anything smaller/lower than a warehouse is OVER...


Ruby - here I come!

You could go with a smaller screen. As Nathan just found out, he will have to mount the pj 16.29" above his 45" high screen.

Ericglo

Would you not need to take the distance screen-pj into account to make this calculation?
____
Axel

You could go with a smaller screen. As Nathan just found out, he will have to mount the pj 16.29" above his 45" high screen.

Ericglo

Right, you buy a 1400 lumen (spec.), 1080p FP just to go with a smaller screen. My screen is (and will remain to be) 10 feet wide - guess I have to build a bigger house then...

Would you not need to take the distance screen-pj into account to make this calculation?
____
Axel

If by calculation you are referring to the height above the screen, then no. That's a fixed offset and it doesn't matter what throw you use.

Best,

Right, you buy a 1400 lumen (spec.), 1080p FP just to go with a smaller screen. My screen is (and will remain to be) 10 feet wide - guess I have to build a bigger house then...


The Ruby has been available for nine months, so you could have bought it already.

Ericglo

The Ruby has been available for nine months, so you could have bought it already.

Ericglo

The Ruby is no option for a 133" screen.

36.2% is a pretty steep angle. I wonder how the fits going to be with my 8' ceilings and 106" diag screen. I see keystoning in my future. :(

Sounds similar to the H27 or DV10's throw angle. I had to use keystone with the H27. Using a cheif mount like I have the center lens is still down 6" from the ceiling. A Optoma or Panvise type mount can put the top of the PJ flat up to the ceiling, though it looks a little funny.

Wish I had 9' ceilings. Hope Wings back on Monday with the first batch like he said, I'm ready to make it work somehow.

Just how bad does keystoning distort the PQ with a newer unit such as this?

36.2% is insane!

Can somebody please explain to me why they would do this?

I have already displayed with a past poll that not only do the majority of users want lens shift but that most of us do have typical 7.5 to 9' ceilings. And we go front projection to have large screens....that is the whole point of all this! I know a few of us have high ceilings or cathedral ceilings and need the offset but again, that is the minority.

I have to say that I too was trying to figure out if I could somehow make the 27% work or hoping it would be less, but 36.2% would makes a 120" screen impossible with 8' ceilings!

Just how bad does keystoning distort the PQ with a newer unit such as this?


I was using keystoning with my projector before I understood what it did, and honestly I was happy with it, given I didn't know any better. Once I learned what keystoning did, I leveled my projector and got rid of the keystoning. I think the picture was noticeably sharper after doing this. The point is that you are buying 1080P so you want to use all of it and I will not buy a projector if I am required to use keystoning...I just couldn't live with it knowing I am cutting off valuable pixels, even if I couldn't see the difference which I can.

I hate to say it but 36% offset appears like it will work in my place... Right now my projector lense center is about 12 inches lower than the bottom of my screen --- and I'm getting a new center channel which will force me to raise the screen a bit.... and now it's looking like 4 inches and change might be the right amount.

That said, I've lived with a projector with horizontal and vertical lense shift for so long, the idea of a fixed offset makes me nervous. And the fact that the projector might work in my current setup is no guarantee that any change to my setup will be easy to accomodate.

12" of extra drop on the electric recessed screen I'm buying plus 12" to 13" off the main ceiling to where I mount it in the soffit. I have 24" to 25". I only need 23.53". Phew!

135" image with the HD81... you are joking, right??? You would need like 9 feet ceilings and a 19 feet long room...at the very least...with your screen touching your floor and the HD81 right at your back wall. Time for a new plan I guess.

No, not joking just lucky... my basement is blessed with a 10' ceiling. However, I did not know what the throw range would be for a 135" diag. image.

36.2% is a pretty steep angle. I wonder how the fits going to be with my 8' ceilings and 106" diag screen. I see keystoning in my future. :(

Sounds similar to the H27 or DV10's throw angle. I had to use keystone with the H27. Using a cheif mount like I have the center lens is still down 6" from the ceiling. A Optoma or Panvise type mount can put the top of the PJ flat up to the ceiling, though it looks a little funny.

Wish I had 9' ceilings. Hope Wings back on Monday with the first batch like he said, I'm ready to make it work somehow.
I also have a 8' ceiling and opting for a 135" diag screen with a 81. I hope that it will work out fine... :)

Bummer,

My hopes are dashed. I was hoping that I could get it to work by tilting me screen and projector. I only have a 7 foot ceiling. :(

Back to more reearch.

Joe

The Ruby is no option for a 133" screen.

Those running the Ruby on 133" high-gain screens in light controlled environments may disagree with you.

Suddenly I'm glad I didn't wait for this projector. I've been doubting the wisdom of buying a 720P PJ, when the HD81 will be arriving in a couple of months. I now know I made the right choice. Even with my 9' ceilings I'd have a problem fitting this PJ in my home. I'd need to completely redesign my TV room.

Will the 2" matter much for the throw? I am getting a 133" diagonal screen. I need to buy a recessed electrical screen for my room setup...

36.2% is insane!

Can somebody please explain to me why they would do this?

I have already displayed with a past poll that not only do the majority of users want lens shift but that most of us do have typical 7.5 to 9' ceilings. And we go front projection to have large screens....that is the whole point of all this! I know a few of us have high ceilings or cathedral ceilings and need the offset but again, that is the minority.

I have to say that I too was trying to figure out if I could somehow make the 27% work or hoping it would be less, but 36.2% would makes a 120" screen impossible with 8' ceilings!

Assuming by 120" you mean width, and assuming a 2:35.1 screen the heght is only 51" (130.4" diagonal (3213mm) 120” width (3048mm) 51.1" (1297mm) height)

Calculations with the PJ hard against the ceiling (assuming the lens 4" down):

51 x 36.2% = 18.5" offset

Add the 4" gives: 22.5" top of screen from the ceiling, puts a 51" tall screen 22.5" off the floor...

Sound about right?

Assuming by 120" you mean width, and assuming a 2:35.1 screen the heght is only 51" (130.4" diagonal (3213mm) 120” width (3048mm) 51.1" (1297mm) height)

Calculations with the PJ hard against the ceiling (assuming the lens 4" down):

51 x 36.2% = 18.5" offset

Add the 4" gives: 22.5" top of screen from the ceiling, puts a 51" tall screen 22.5" off the floor...

Sound about right?

Wow, I didn't consider the lens distance from the ceiling. Oh well, that settles it, I have to get a Ruby or wait for another front projector. Did someone say the Ruby won't work well at a distance of 17' to 22' from a 133" diagonal projection screen?

- Jeff

Al,

I think you are assuming that they are doing a CH 2.35 screen which will add extra money for an anamorphic lens and mounting hardware for the lens... and can you even get an anamorphic lens that close to the ceiling in front of the projector?

Personally I would think that the majority of folks buying this projector would be using a 16x9 screen instead, just a guess on my part but I from my experience it is a fairly small group that is willing to put up with the additional hassle to make a 2.35 screen work, unless they are watching nothing but movies with their projector.

I belong to the "other" group of crazies that use the projector for everything! Even the evening news... I know I am nuts... but hey we all have "issues." :-)

Tom (Guitarman)... being that the offset has changed from the original post, could you ask Mr. Wing if the throw range has also changed?

Al,

I think you are assuming that they are doing a CH 2.35 screen which will add extra money for an anamorphic lens and mounting hardware for the lens... and can you even get an anamorphic lens that close to the ceiling in front of the projector?

Personally I would think that the majority of folks buying this projector would be using a 16x9 screen instead, just a guess on my part but I from my experience it is a fairly small group that is willing to put up with the additional hassle to make a 2.35 screen work, unless they are watching nothing but movies with their projector.

I belong to the "other" group of crazies that use the projector for everything! Even the evening news... I know I am nuts... but hey we all have "issues." :-)

You are right on all accounts! ;) Actually I would guess that 70+% of the hours on my PJ are 16x9 viewing. The CH 2.35:1 is the newest plan using SMX720.

And yes a 2.35:1 screen is not as common as 16x9, in fact that's what I currently have. But just as a comparison, I have a 106" diagonal screen and it's height is 51.5" hence my example of a 51" high 2.35:1 screen.

My basement HT setup (only roughed in right now) can't take a screen larger then 51-52" so my plan was a screen that was no smaller the the current one for 16x9 viewing but could also expand out to 120" wide for a 2.35:1 movie. I am looking at the Prismisonic HD85 for use with the HD81. As for mounting the lens, creativity will have to be the order of the day to get the entire assembly that close to the ceiling!

The latest news about the offset on this PJ is beginning to tax it's ability to fit into too many "regular" rooms, too bad because it sounds like a great combo setup with the scaler. As long as no new changes pop up I may still be able to integrate it into my room.

The latest news about the offset on this PJ is beginning to tax it's ability to fit into too many "regular" rooms, too bad because it sounds like a great combo setup with the scaler. As long as no new changes pop up I may still be able to integrate it into my room.

It is odd designing if the new offset is true IMO... The price point is catered to the mass market, yet the new offset isn't. Seems like the left hand didn't know what the right hand was doing when they were engineering it. :confused:

Tom (Guitarman)... being that the offset has changed from the original post, could you ask Mr. Wing if the throw range has also changed?

Sure, it's interesting he took time to chime in with the offset info, he was in Taiwan this last week. Next week's HD81 time if everything went well.

I realize many people have room and ceiling height constraints that don't allow for optimal setup for this projector, but for those who have a dedicated theater with the right space, this looks GREAT!
http://home.comcast.net/~scottj0007/theater/optoma_3.jpg

How accurate is the rumor that this will come in at $6000 street price?

Nice job Scott that looks ideal. I'll have no problem with my 8' ceiling and a 106" diag screen.

Scott:

The problem with this setup is that you either must have an acoustically transparent screen or your center channel will have to be placed practically on the floor.

How accurate is the rumor that this will come in at $6000 street price?

That should be it, the plan was to compeet with the Ruby street price and better.

Humph... :mad: Perhps I will add extra length to my screen so I can use this projector. It is getting awfully close to the floor. :(

Scott:

The problem with this setup is that you either must have an acoustically transparent screen or your center channel will have to be placed practically on the floor.


My center channels top is 18" up from the floor 120" sceen would work, 106" even better.

Nah, can't do it, my center channel will block part of the screen, oh well...

The problem with this setup is that you either must have an acoustically transparent screen or your center channel will have to be placed practically on the floor If you place the screen any higher on the wall, then you will be looking up at more than a 15 degree angle, which also is not an ideal setup according to THX. In all setups that I know of, your only options are either an acoustically transparent screen (which usually involves some screen compromises), or placing the center speaker directly below the screen (which usually involves some audio compromises). This becomes a matter of personal opinion but I really like the acoustically transparent screen option. It seems to me that Optoma went with the projector design that would result in the best "ideal" theater setup with the fewest compromises. I don't know if this was the right business decision on their part, but it is good for those people who can make it work. (IMHO :) )

I realize many people have room and ceiling height constraints that don't allow for optimal setup for this projector, but for those who have a dedicated theater with the right space, this looks GREAT!
http://home.comcast.net/~scottj0007/theater/optoma_3.jpg

Yep, exactly what I said, great diagram too!

As I said earlier, my current screen is a 52x92 106" diagonal screen, a 2.35:1 at 120" wide yields a 51" high screen and fits the diagram you posted.

Now I realize that the option of an acoustically transparent screen is not for everybody, so I just wanted to share that my current screen is 26.5" above the floor and the center channel speaker is below (15" to speaker center) and faced slightly upward. For the most part the on screen vocals work quite well and has never been an issue for any visitors either. Not necessarily idea but very functional.

Now I realize that the option of an acoustically transparent screen is not for everybody, so I just wanted to share that my current screen is 26.5" above the floor and the center channel speaker is below (15" to speaker center) and faced slightly upward. For the most part the on screen vocals work quite well and has never been an issue for any visitors either. Not necessarily idea but very functional.

My center channel speaker would eventually be 25.6" off the ground, my screen 133" diagonal (65" image height) and my ceiling will be 9' to 9' 1". The speaker would have to be either blocking part of the screen or behind the screen for me to use this projector. How well do the Da-Lite permeable screen materials work as far as sound quality from a speaker behind the screen (on the tensioned ceiling recessed advantage electrol screens)? How does the acoustically transparent material effect the visual quality of the material being presented on the screen?

Thanks

That should be it, the plan was to compeet with the Ruby street price and better.

Sounds good to me, as long as it has better brightness than the ruby.

Assuming by 120" you mean width, and assuming a 2:35.1 screen the heght is only 51" (130.4" diagonal (3213mm) 120” width (3048mm) 51.1" (1297mm) height)

Calculations with the PJ hard against the ceiling (assuming the lens 4" down):

51 x 36.2% = 18.5" offset

Add the 4" gives: 22.5" top of screen from the ceiling, puts a 51" tall screen 22.5" off the floor...

Sound about right?

No, I mean 120" diagonal 1.78:1 and I am really at about 123" diagonal

So that will mean 59x.362 = 21.4 offset plus 4" puts my screen 25.4 inches down. Which puts my screen about 11" off the ground....

akosoft, I assume with your 135" screen that you are using a 2.35:1 screen or your screen would be just a little over 2" off the ground with a 1.78:1 and assuming lens was 4" below ceiling.

This big an offset just doesn't make sense....I guess I will be skipping this projector....I hope they add offset for the next generation of this projector as it looks promising otherwise.

@dangc

My mistake!,

I mean 8' ceiling and (1:78) 106" diag screen, not 135"!. (just like the Guitarman). So there's still hope for me!? :)

I realize many people have room and ceiling height constraints that don't allow for optimal setup for this projector, but for those who have a dedicated theater with the right space, this looks GREAT!
http://home.comcast.net/~scottj0007/theater/optoma_3.jpg




Works for me...now we just need some final product reviews....and in my case....a great street price. :)

For those who might be interested...

I modified my calculator with the new offset.

Joe

(edit: added 2.35:1 calc)
(edit: added throw calcs)

Scott:

The problem with this setup is that you either must have an acoustically transparent screen or your center channel will have to be placed practically on the floor.

Or above the screen angled downward. The avaialable space is rougly equal.

Dennis Erskine has indicated that generally above is better than below if one cannot place behind the screen.

Wow, I didn't consider the lens distance from the ceiling. Oh well, that settles it, I have to get a Ruby or wait for another front projector. Did someone say the Ruby won't work well at a distance of 17' to 22' from a 133" diagonal projection screen?

- Jeff

Yes, the Ruby will work within that throw.

From a brightness standpoint, the shorter throw the better. For that size screen you can get the Ruby a close as ~14', but 17' should not give up too much light.

I modified my calculator with the new offset.

Thanks for a great contribution to this thread. This is very helpful.

Yes, the Ruby will work within that throw.

From a brightness standpoint, the shorter throw the better. For that size screen you can get the Ruby a close as ~14', but 17' should not give up too much light.

Good, at least I have a backup plan then. Thanks.

Thanks for a great contribution to this thread. This is very helpful.

Thanks. Let me know if it needs any enhancements.

Joe

No, I mean 120" diagonal.78:1 and I am really at about 123" diagonal

So that will mean 59x.362 = 21.4 offset plus 4" puts my screen 25.4 inches down. Which puts my screen about 11" off the ground....

akosoft, I assume with your 135" screen that you are using a 2.35:1 screen or your screen would be just a little over 2" off the ground with a 1.78:1 and assuming lens was 4" below ceiling.

This big an offset just doesn't make sense....I guess I will be skipping this projector....I hope the add offset for the next generation of this projector as it looks promising otherwise.

Wow that's a huge 16x9 screen, yep a 59" high screen does present a problem especially in a regular height room.

No point in suggesting anything else, it has all been said in this thread already... bummer!

@dangc

My mistake!,

I mean 8' ceiling and (1:78) 106" diag screen, not 135"!. (just like the Guitarman). So there's still hope for me!? :)

Me too! Right now I have a 52x92 16x9 and anything else I install will not be taller only wider so my fingers are crossed! :)

My center channel speaker would eventually be 25.6" off the ground, my screen 133" diagonal (65" image height) and my ceiling will be 9' to 9' 1". The speaker would have to be either blocking part of the screen or behind the screen for me to use this projector. How well do the Da-Lite permeable screen materials work as far as sound quality from a speaker behind the screen (on the tensioned ceiling recessed advantage electrol screens)? How does the acoustically transparent material effect the visual quality of the material being presented on the screen?

Thanks

I don't have any direct experience with the AT screens of any brand, but as a general rule you will loose some brightness due to the perforations, how much depends on the amount of "openness". This varies between screen types and the manufacturer's specs should be consulted.

The SMX720 screen material that I have recently purchased has an openness of 5% and a gain of 1.16. This is a DYI screen material sold at another location, all reports that I have read have been quite positive but as usual YMMV. ;) There are a number of individuals working on ideas for making a retractable screen with this material too.

For me the opportunity to get the center speaker closer to the idea position and make a 2.25:1 screen in the process made this adventure worth starting.

If you are interested check out the SMX Forum www.smxscreen.com and apparently the material will back in stock next month.

I'm very disappointed about the new offset also. I have 7' ceilings so I've got a big problem. I'd really like to find a way to make this projector work, so I've been thinking about Mr Wiggles' technique for angling the projector up and angling the screen forward so that the relationship between the PJ and screen remains the same, but you can mount the screen higher. If my math is correct, I could angle the projector up about 5 degrees and angle screen forward about 5 degrees. That leaves the angle between the projector and screen exactly the same. If I use a 120" screen, the screen height would be 58". This would require the top to be tilted forward about 5". I'm trying to figure if that would be objectionable looking. If I lower the screen, I could lessen the tilt.

Mr Wiggles, have you seen setups with forward tilts in that range? How did they look? And do you remember me from the LT100 days? I was one of the people who kept getting caught up in those banding discussions with Larry Davis.

Thanks

Joe

Thanks. Let me know if it needs any enhancements.

Joe

Are you assuming the use of an anamorphic lens for your 2.35:1 calculations? If not, then I think your figures are wrong. With no anamorphic lens, you're still projecting a 16x9 image and the 2.35:1 image is vertically centered on this area resulting in a significant drop of the image on the screen. Plus an anamorphic lens could change the offset.

Joe...... I wish to add my thanks for the calculator..............

and there is one adjustment I might suggest...... How about throwing in a throw calculation at the same time (min - max)?

Are you assuming the use of an anamorphic lens for your 2.35:1 calculations? If not, then I think your figures are wrong. With no anamorphic lens, you're still projecting a 16x9 image and the 2.35:1 image is vertically centered on this area resulting in a significant drop of the image on the screen. Plus an anamorphic lens could change the offset.

I have added no lens factors specifically but assuming the final image on the screen ends up at 2.35:1 does it matter how it got there from a vertical standpoint? Would it change the offset %? I have not done tons of reading on the anamorphic lenses but I thought they "unstretched" the vertical "stretch" done with the scaler.

Anyway...

If there are lens calcs that I should add I will be more than happy to. Let me know what they are an I will build them in.

Joe

Joe...... I wish to add my thanks for the calculator..............

and there is one adjustment I might suggest...... How about throwing in a throw calculation at the same time (min - max)?

Thanks.

I have added the throw ratios of 1.8 and 2.2 which are from the first page of this thread. If they have changed please let me know.

Joe

all this trouble for a projector that no one has their hands on yet? I dont know about the rest of you but I was interested in this projector when it was announced but quickly realized that the throw and offset wouldnt work, flexibility is key in my theater because I know that I wont have one projector for all eternity so building an extensive solution around something that wasnt released yet wasnt an option as again I see specs changing and people scrambling to find a solution, I have a Ruby that is tons more flexible than this, more than one digital input, flexible installation with motorized Zoom,horizontal AND vertical lens shift, not one but two digital inputs(dvi,hdmi) and with my 110" hipower screen brightness is more than enough. I am not saying that the projector I chose is right for everyone but if those of you on the fence would hold on for more projector options I thinks it will be well worth the wait, as I read the thread it seems like an awful lot of stress to accomodate something that someone hasnt laid hands on yet especially with optomas past rep with bulbs and service.

all this trouble for a projector that no one has their hands on yet? I dont know about the rest of you but I was interested in this projector when it was announced but quickly realized that the throw and offset wouldnt work, flexibility is key in my theater because I know that I wont have one projector for all eternity so building an extensive solution around something that wasnt released yet wasnt an option as again I see specs changing and people scrambling to find a solution, I have a Ruby that is tons more flexible than this, more than one digital input, flexible installation with motorized Zoom,horizontal AND vertical lens shift, not one but two digital inputs(dvi,hdmi) and with my 110" hipower screen brightness is more than enough. I am not saying that the projector I chose is right for everyone but if those of you on the fence would hold on for more projector options I thinks it will be well worth the wait, as I read the thread it seems like an awful lot of stress to accomodate something that someone hasnt laid hands on yet especially with optomas past rep with bulbs and service.

Naw, this is fun stuff!! Don't rain on our parade :p Maybe you should change your handle from funlvr to ptypupr ;)

Seriously,

I tried a Ruby and being I have an AT screen and a multi-purpose area of which the theater is just one part the Ruby didn't do it for me. This is the 2nd decently priced 1080p projector to come out. If it doesn't work I will look at the next one. And so on and so on...

Joe

Seriously,

I tried a Ruby and being I have an AT screen and a multi-purpose area of which the theater is just one part the Ruby didn't do it for me. This is the 2nd decently priced 1080p projector to come out. If it doesn't work I will look at the next one. And so on and so on...

Joe

good deal, keep your options open, when was spending 6k on something that might not work "fun"?

I have added no lens factors specifically but assuming the final image on the screen ends up at 2.35:1 does it matter how it got there from a vertical standpoint? Would it change the offset %? I have not done tons of reading on the anamorphic lenses but I thought they "unstretched" the vertical "stretch" done with the scaler.

Anyway...

If there are lens calcs that I should add I will be more than happy to. Let me know what they are an I will build them in.

Joe

Let me try to explain this a bit differently - If there is no anamorphic lens, you've set your calculations up based on a constant width configuration meaning zoom ratios are not changed. Normally, a 2.35:1 image is letter boxed onto a 16x9 format. Therefore, the image drop to the top of the 16x9 window is the same for for both formats, the only difference being the 2.35:1 image is centered on the 16x9 window. Thus the top of the 2.35 image will positioned at the lens offset plus the difference in height between 16x9 and 2.35:1 divided by 2.

Let me try to explain this a bit differently - If there is no anamorphic lens, you've set your calculations up based on a constant width configuration meaning zoom ratios are not changed. Normally, a 2.35:1 image is letter boxed onto a 16x9 format. Therefore, the image drop to the top of the 16x9 window is the same for for both formats, the only difference being the 2.35:1 image is centered on the 16x9 window. Thus the top of the 2.35 image will positioned at the lens offset plus the difference in height between 16x9 and 2.35:1 divided by 2.

Yep, got it. That makes sense.

But then you scale the image to use all pixals and then send it through the anamorphic lens, right? So, after doing that, how do the calculations change?

Joe

Yep, got it. That makes sense.

But then you scale the image to use all pixals and then send it through the anamorphic lens, right? So, after doing that, how do the calculations change?

Joe

I think this depends on the lens, but your calculations will be closer in this situation.

I'm very disappointed about the new offset also. I have 7' ceilings so I've got a big problem. I'd really like to find a way to make this projector work, so I've been thinking about Mr Wiggles' technique for angling the projector up and angling the screen forward so that the relationship between the PJ and screen remains the same, but you can mount the screen higher. If my math is correct, I could angle the projector up about 5 degrees and angle screen forward about 5 degrees. That leaves the angle between the projector and screen exactly the same. If I use a 120" screen, the screen height would be 58". This would require the top to be tilted forward about 5". I'm trying to figure if that would be objectionable looking. If I lower the screen, I could lessen the tilt.

Mr Wiggles, have you seen setups with forward tilts in that range? How did they look? And do you remember me from the LT100 days? I was one of the people who kept getting caught up in those banding discussions with Larry Davis.

Thanks

Joe
Wow, no I did not remember you, but now I do. I think it came down to the UP1100 and the LT100 not being identical projectors and banding could occur with some two out of the three gamma settings. I eventually posted photos of my test images. Those were the days.

Anyway, I have seen tilts that were in the 5" (roughly 6 degrees) range that were not objectionable. The key is how the center of the screen faces your audience. You don't want the center of the screen to face below the audiences line of sight.

-Mr. Wigggles

I have updated the calculator. It now includes the min and max throw calculations, a section for constant width 2.35:1, and the angle calculations need to eliminate the offset based on the min and max throws (thanks to Joe Linn for the angle calculations.).

Joe

Alright guys,

EDIT: I tried to make the diagram as tight as possible and I thought I was at 7', but as it turns out, it is actually 6'4".

With 6'4" ft ceiling and a 104" diagonal screen you can still squeeze this projector in. I simply rotated Scott's image 5 degrees and moved the seating position a little closer.

http://mrwigggles.250free.com/optoma_3_tilted.JPG

It fits barely. Basically, the screen starts 22" from the floor and goes to 3" from the ceiling. The chair 9.5 feet away has 1.25:1 viewing ratio, so it isn't too close. The projector is on the ceiling.

I drew a right angle line from the center of the screen to the viewer and it hits the viewer right in the eyes. So, to this viewer the screen would be square on and would not appear to be tilted down.

Now, if you wanted to put two rows in, you would be in a little bit of trouble. You would either need to use bean bags or something very low in the front. A 36" high viewing position can't really go any further back or the screen is going to look tilted down. You could put a low 30" viewing position 12 feet back and a 24" viewing position 8 feet back, but good luck finding such furniture.

Bottomline: It is possible to do a 7 foot install if you plan everything perfectly and don't mind having only one row of real seating. Two rows is going to be tricky.

-Mr. Wigggles

I have updated the calculator. It now includes the min and max throw calculations, a section for constant width 2.35:1, and the angle calculations need to eliminate the offset based on the min and max throws (thanks to Joe Linn for the angle calculations.).

Joe

Hi Joe,

There are two types of anamorphic lenses for a 2.35:1 constant height (not width ;) ) setup. Your calculations are correct for a vertical compression lens (VC), but are not for a horizontal expansion (HE) lens. I mention this as the install of the projector is significantly different depending on which lens is used.

For the same size screen with a VC lens you would use your calculations in the 2.35 section (110.4" wide, 47" high screen using a 120" 2.35 for eg). For an HE lens you would use the calculations in the 16:9 section (entering in an 83.5" 16:9 screen width, same 47" high).

This essentially results in a shorter throw for an HE lens and longer throw for a VC lens.

Mike

I haven't followed this thread for a while so it might have already been posted, but I understand the lens offset is now 38%. This becomes very problematic for all but the highest ceilings. Can anyone verify this?
I've been away for a while doing installs and Wife's BD, however since I was the first to make this public service announcement, I am accepting contributions in the form of gift certificates at Roy's Hawaiian Fusion or Paul Fleming's Steaks. Especially from those who doubted my voracity.

So what is the best thing to do

1 Angle the projector and screen and avoid keystone correction but will you not risk soft focus?

2 Level projector and screen when possible but use keystone. Does VXP offer advanced keystone that lowers picture quality only some?

You guys are working awfully hard to figure out a way to get this PJ to work in a reasonable installation.

I am going to wait for the BenQ or Sharp 1080p.

So what is the best thing to do

1 Angle the projector and screen and avoid keystone correction but will you not risk soft focus?

Would there be soft focus if the lense is perpendicular to the screen (which is to say you've tilted them both the same amount)?

You guys are working awfully hard to figure out a way to get this PJ to work in a reasonable installation.

I am going to wait for the BenQ or Sharp 1080p.

I'm not doing the room construction until around May now. By then I should have more choices besides the Ruby and HD81, since that only leaves me with one choice anyway because the HD81 is too inconvenient to install in my space if I want to use a decent center channel that will match my left and right front speakers...

I'll have to check out the BenQ and Sharp 1080p, thanks for listing them. :cool:

There is no reason that tilting would cause a change in focus provided the distance from the top of the screen to projector and bottom of screen to projector don't change. So long as the orientation of projector to screen remains the same, the focus (keystone/everything else between projector and screen) remains the same as well.

Whether or not you want to go throught the trouble is a different matter.

For those who might be interested...

I modified my calculator with the new offset.

Joe

(edit: added 2.35:1 calc)
(edit: added throw calcs)


Joe,
Let me add my thanks for this calculator - very useful!

Can anyone confirm that mounting the projector so that the center of the lens is 4" down from the ceiling is readily achievable?

Thanks,
Mike

Would there be soft focus if the lense is perpendicular to the screen (which is to say you've tilted them both the same amount)?

No, my thinking would be if you tilted the projector and not the screen you run a chance of softer focus (not perpindicular to screen) and loss of resolution (keystone correction).

Fortunately the HD81 works perfectly in my current setup (have an HD72 with similar offset) and don't have to do either. This is the front runner for 1080p upgrade right now, but I'm pretty pleased with the HD72 so I can wait for the 1080p battles next year and see what happens...

Mike

You guys are working awfully hard to figure out a way to get this PJ to work in a reasonable installation.

I am going to wait for the BenQ or Sharp 1080p.
There was a time before lens-shift when all projector installs required a little geometry with the good ol' pencil and paper to make them fit. I don't find any of this "working hard". You only have to work hard for very low ceilings as in my 6'4" example.

The Optoma is likely going to be the brightest and sharpest thing around when it comes out because the optics are borrowed from another projector and are more simplistic than other super-zoom projectors. Simpler optics usually means brighter images with better sharpness.

They have officially announced the target street price as $6K. I seriously doubt the Sharp will be less than $10K street and I would guess the BenQ is a ways off given that no one has even seen a prototype of it yet (anyone?)

So a little geometry work can say you thousands of dollars and give you the most competent image around. From reactions I have heard from those who have seen the Optoma and the measurements GregR did on the Marantz, I think it is very likely that the Optoma will have a "better" image than the $20K MSRP Marantz.

Saving close to $14K is worth just a little bit more effort. My definition of "hard work" is all the extra OT at the day job it would take to make-up for the near $14K difference.

-Mr. Wigggles

I got word the HD3000 Scaler sold alone will be the full $2999, no internet show downs or low MAP for this device. Kinda raises the bar on the HD81.

Much is made of the effect of the Gennum VXP processor in the Marantz. Is this the same Gennum processor that is in the HD-81?

The HD3000 scaler only adds 2000 to the price of the 7100 or 7300 as it's called. Seems like 2000 retail and even less at street price if the pricing follows the other projector. That is the same scaler right as listed here http://www.ultimateavmag.com/videoprojectors/606optomahd7100/

MrWigggles
Are you expecting the HD81 lens to be sharper the supposedly uber lens in VP-11S1?

The HD3000 scaler only adds 2000 to the price of the 7100 or 7300 as it's called. Seems like 2000 retail and even less at street price if the pricing follows the other projector. That is the same scaler right as listed here http://www.ultimateavmag.com/videoprojectors/606optomahd7100/

That would be the same scaler except it's locked for 720p output. The scaler alone we thought would street price at a MAP of $1500 but that's changed. MAP is $2999. You're getting a deal when buying the HD7300 because you won't see the scaler selling for less or even near that 2k difference.

The scaler has the later Gennum chip in it I assume the Marantz has the same one.

I got word the HD3000 Scaler sold alone will be the full $2999, no internet show downs or low MAP for this device. Kinda raises the bar on the HD81.

Tom were you able to find out if the throw has changed in addition to the offset... or is it still as previously quoted?

Also........

What type of cable is running from the scaler to the projector?

Is it standard HDMI or some type of proprietary cable? (just curious as I already have one in the ceiling...)

I think it is very likely that the Optoma will have a "better" image than the $20K MSRP Marantz. Maybe, if a rather long series of assumptions turn out to be true and there aren't ANY other issues we are not yet aware of. Given the original tentative claims about the HD81's offset and MAP pricing of the HD3000 processor, it seems to me that some healthy skepticism about the particulars of a yet-to-be-released product is warranted. Speaking for myself:

a 1.25 viewing distance (eliminates those who prefer not to sit in the front rows of a theater)
tilted screen (eliminates those who want an electrical drop-down)
screen placement close to floor (eliminates those without an acoustically transparent screen and those who don't want the center channel on the floor or ceiling)
custom ceiling mount (rules out shelf mount)

is working pretty hard. By "working" I mean you are willing to make all kinds of compromises for installation that a lot of people would otherwise not make in a market crowded with more user-friendly products.

But, this is a matter of personal taste. Each to his own.

From reactions I have heard from those who have seen the Optoma and the measurements GregR did on the Marantz, I think it is very likely that the Optoma will have a "better" image than the $20K MSRP Marantz.

Saving close to $14K is worth just a little bit more effort. My definition of "hard work" is all the extra OT at the day job it would take to make-up for the near $14K difference.

-Mr. Wigggles

And it would certainly also be nice if it does in fact produce the 900 calibrated lumens that TzungILin reported in post #1. IRRC, the Marantz comes in at 300 something.

Also........

What type of cable is running from the scaler to the projector?

Is it standard HDMI or some type of proprietary cable? (just curious as I already have one in the ceiling...)

One HDMI input and a RS232 is all the inputs the projector will have. Digital cables can be fussy, lets hope we don't have problems. I got a clean image to the HD7100 with a 25' mono cables HDMI cable.

I'll find out about the throw. Wing's going to email me when the first batch arrives, hope it's this week. There will be some dealers selling off the first batch and second batch arrives just a couple of weeks later. I'd call AVS ask them if they're getting one and snag it. :)

As soon as I get the email I'll post it.

How does the offset of the HD81 compare to the offset of the NEC HT1000? I didn't have any trouble installing the HT1000 in a room with 8' ceilings, but I did mount my center channel speaker above the screen. Works for me!

Thanks Tom,

It will be an interesting next 12 months or so......

I also am running a 25' Mono HDMI from my receiver to my 7210 (of course it needs an HDMI/M1 converter on the end of it, so it), so it would be great if that same cable would function here also.

There was a time before lens-shift when all projector installs required a little geometry with the good ol' pencil and paper to make them fit. I don't find any of this "working hard". You only have to work hard for very low ceilings as in my 6'4" example.

The Optoma is likely going to be the brightest and sharpest thing around when it comes out because the optics are borrowed from another projector and are more simplistic than other super-zoom projectors. Simpler optics usually means brighter images with better sharpness.

They have officially announced the target street price as $6K. I seriously doubt the Sharp will be less than $10K street and I would guess the BenQ is a ways off given that no one has even seen a prototype of it yet (anyone?)

So a little geometry work can say you thousands of dollars and give you the most competent image around. From reactions I have heard from those who have seen the Optoma and the measurements GregR did on the Marantz, I think it is very likely that the Optoma will have a "better" image than the $20K MSRP Marantz.

Saving close to $14K is worth just a little bit more effort. My definition of "hard work" is all the extra OT at the day job it would take to make-up for the near $14K difference.

-Mr. Wigggles

I interpreted his quote a little differently. I thought he was noticing how the offset was making the average install space hard to work with, but that was probably just me projecting (no pun intended) because my space, while spacious, still can't accommodate the HD81 without sacrificing a decent center channel or a decent center channel setup.

Maybe, if a rather long series of assumptions turn out to be true and there aren't ANY other issues we are not yet aware of. Given the original tentative claims about the HD81's offset and MAP pricing of the HD3000 processor, it seems to me that some healthy skepticism about the particulars of a yet-to-be-released product is warranted. Speaking for myself:

a 1.25 viewing distance (eliminates those who prefer not to sit in the front rows of a theater)
tilted screen (eliminates those who want an electrical drop-down)
screen placement close to floor (eliminates those without an acoustically transparent screen and those who don't want the center channel on the floor or ceiling)
custom ceiling mount (rules out shelf mount)

is working pretty hard. By "working" I mean you are willing to make all kinds of compromises for installation that a lot of people would otherwise not make in a market crowded with more user-friendly products.

But, this is a matter of personal taste. Each to his own.

Ah, I did interpret it correctly...

I think Mr. Wiggles comments are asking us to reflect a bit... yes there are more and more "consumer friendly" electronics coming out all the time, but it was not that long ago that dealing with this type of installation difficulty would seem trivial.

Now, I am not letting Optoma off the hook here... or just being a fan-boy (I don't even own an Optoma... yet), but I think that Optoma was forced into several compromises in order to get to market as quickly as they are... and to hit the price points they wanted to hit.

It is unfortunate that some of these compromises are making the projector difficult to work with for many who would have stepped up and purchased one... so in fact Optoma will bear the fruits of their decisions... whether for good or for ill. I am grateful that they are trying to push the technological and price boundaries at the same time. You may not want to fly on Southwest Airlines all the time..., but be darn grateful they are out there because they have made travel more affordable, no matter whose jet you fly on!

As to difficult.... my daughter who has 3 children had the door to her washer broken by a sibling trying to "help." Now she is doing the families laundry in the bath-tub and hanging them on a line... she has gained an immense appreciation for the daily travail of those who have passed before us. Perspective is an amazing thing.......

I think Mr. Wiggles comments are asking us to reflect a bit... yes there are more and more "consumer friendly" electronics coming out all the time, but it was not that long ago that dealing with this type of installation difficulty would seem trivial.

Now, I am not letting Optoma off the hook here... or just being a fan-boy (I don't even own an Optoma... yet), but I think that Optoma was forced into several compromises in order to get to market as quickly as they are... and to hit the price points they wanted to hit.

It is unfortunate that some of these compromises are making the projector difficult to work with for many who would have stepped up and purchased one... so in fact Optoma will bear the fruits of their decisions... whether for good or for ill. I am grateful that they are trying to push the technological and price boundaries at the same time. You may not want to fly on Southwest Airlines all the time..., but be darn grateful they are out there because they have made travel more affordable, no matter whose jet you fly on!

As to difficult.... my daughter who has 3 children had the door to her washer broken by a sibling trying to "help." Now she is doing the families laundry in the bath-tub and hanging them on a line... she has gained an immense appreciation for the daily travail of those who have passed before us. Perspective is an amazing thing.......

I think I see your point. Your daughter can't afford a new washing machine. Perhaps you should buy her a new one and get a projector next year. :p

"1 Angle the projector and screen and avoid keystone correction but will you not risk soft focus?"

Not if done correctly.

It can be thought of as starting with a normal setup that's in focus, and tilting the pj and screen as a unit, which will therefore remain in focus.

I think I see your point. Your daughter can't afford a new washing machine. Perhaps you should buy her a new one and get a projector next year. :p

WHAT...... sacrifice in the Home Theater..... what are you some kind of kook!

We must have our Priorities..!!! :eek:

Maybe, if a rather long series of assumptions turn out to be true and there aren't ANY other issues we are not yet aware of. Given the original tentative claims about the HD81's offset and MAP pricing of the HD3000 processor, it seems to me that some healthy skepticism about the particulars of a yet-to-be-released product is warranted.
I wouldn't consider them a long series of assumptions. They have specifically stated in a press-release which was latter confirmed by multiple representatives that the street price target is $6K.

Speaking for myself:

a 1.25 viewing distance (eliminates those who prefer not to sit in the front rows of a theater)
tilted screen (eliminates those who want an electrical drop-down)
screen placement close to floor (eliminates those without an acoustically transparent screen and those who don't want the center channel on the floor or ceiling)
custom ceiling mount (rules out shelf mount)

You guys are working awfully hard to figure out a way to get this PJ to work in a reasonable installation.
Most of those items you listed are only necessary in my extreme example. MOST people don't have 7FT ceilings in their HT's (much less 6'4" ceilings) and are thus much more "reasonable". But if they do have 7FT ceilings, they will probably need SOME tilt but not as much as I showed. With less tilt, they don't have to sit 1.25 screen widths away. (however, much further back and you won't be able to see all of the benefits of 1080p anyway.)

I think you should have originally stated "this looks like too much hard work for me."

-Mr. Wigggles

I wouldn't consider them a long series of assumptions. They have specifically stated in a press-release which was latter confirmed by multiple representatives that the street price target is $6K.


Most of those are only necessary in my extreme example. MOST people don't have 7FT ceilings in their HT's (much less 6'4" ceilings). If they do, they will probably need SOME tilt but not as much as I showed. With less tilt, they don't have to sit 1.25 screen widths away. (however, much further back and you won't be able to see all of the benefits of 1080p anyway.)

I think you should have originally stated "this looks like too much hard work for me."

-Mr. Wigggles

In my case, I can't do it without placing my center channel in a bad position for 5.1 music playback and/or without using a center that doesn't match my setup. I was excited about this unit and the original offset would have worked perfectly! The tilt won't work for me with the tensioned electric screen I have to use because my room dimensions are very long and my system is set up for optimal 2-channel listening. The HTM1D center channel that matches my other front speakers is over 25" tall with the spikes on it. It would have been nice if the engineer posted these changes when he knew about them; it seems he just posted and disappeared (though I admit, I didn't read the entire thread, I don't have the time).

WHAT...... sacrifice in the Home Theater..... what are you some kind of kook!

We must have our Priorities..!!! :eek:

LOL. I admit, sometimes my priorities get screwed up. I'm working on spending everything on audio, but my wife always gets in the way... :o

"Honey, but the kids need clothes."
"Honey, but the kids need peanut butter and jelly for lunch all week."

Hogwash! Humans ran around naked and foraged for food long before I ever came along and look where it got them.

That would be the same scaler except it's locked for 720p output.

Tom,

What does this mean? I was hoping to purchase the hd7300 and maybe upgrade to a future version of the hd81 projector when available. If it is locked at 720p will I be able to do this?

Joe

I suppose a firmware could open it. But the HD81 will be sold as a two part system, that's another problem.

There was a time before lens-shift when all projector installs required a little geometry with the good ol' pencil and paper to make them fit. I don't find any of this "working hard". You only have to work hard for very low ceilings as in my 6'4" example.

The Optoma is likely going to be the brightest and sharpest thing around when it comes out because the optics are borrowed from another projector and are more simplistic than other super-zoom projectors. Simpler optics usually means brighter images with better sharpness.

They have officially announced the target street price as $6K. I seriously doubt the Sharp will be less than $10K street and I would guess the BenQ is a ways off given that no one has even seen a prototype of it yet (anyone?)

So a little geometry work can say you thousands of dollars and give you the most competent image around. From reactions I have heard from those who have seen the Optoma and the measurements GregR did on the Marantz, I think it is very likely that the Optoma will have a "better" image than the $20K MSRP Marantz.

Saving close to $14K is worth just a little bit more effort. My definition of "hard work" is all the extra OT at the day job it would take to make-up for the near $14K difference.

-Mr. Wigggles

I have to agree, for me the current specs of the HD81 can be delt within a reasonbly sized room with a 8 foot ceiling.

Now all I have to do is decide if making a curved screen to go along with this PJ is worth the extra work! :rolleyes:

Guitarman, i was hoping for some hd81 results, not just another post, :p

Who's heard of the Optoma H80 a one piece design http://www.pjreview.com/forum/viewtopic.php?t=31 http://images.cinenow.com/reports/2005_cedia_us/Optoma/cedia-us-05-optoma-008.jpg

I suppose a firmware could open it. But the HD81 will be sold as a two part system, that's another problem.

I understand.

I guess with my naive hopes I was thinking that down the road a bit Optoma would come out with a version of the HD81 that had more placement configuration options. Including a one-piece offerering like the rumors of the HD80.

My ceiling is 6'4" so I am in a real tough spot trying to use the HD81.

What to do.... What to do....

Joe

I understand.

I guess with my naive hopes I was thinking that down the road a bit Optoma would come out with a version of the HD81 that had more placement configuration options. Including a one-piece offerering like the rumors of the HD80. What to do.... What to do.... Joe

I would certainly imagine that Optoma's next generation 1080p pj will have lens shift, but that is probably a year from now.

After this becomes a knowable product I'm hoping that I can sit it on a tabletop behind my couch in the living room which is about 16 feet to the Graywolf 106" screen. It can sit dead middle to either side but would be on the lower third of the screen to the lens.

Looking forward to hearing more about the results when Guitarman has digested. Shoot, hook that sucker up to a Toshiba HD-DVD too when you can. :)

Mr. Wiggles (or anybody else for that matter):

Can you help me figure out how much screen/projector tilt I'd need to use the HD81 in my theater?

My screen is 51" high and exactly 13.5" from the ceiling to the top of the screen. With my screen size, I'll need an offset of 18.5". Assuming that the center of the projector lens can be mounted no closer than 4" to the ceiling, my offset shrinks to 13.5 - 4 = 9.5". I need to make up the missing 18.5 - 9.5 = 9" by tilting the screen and the projector. My projector lens will be ~200" from the screen.

How many degrees will I need to tilt, and what does this translate to in terms of inches that I'll need to either pull forward the top edge of the screen or push back the bottom edge of the screen? Thinking in terms of distance will make it easier to visualize how noticeable this tilt will be.

Thanks in advance. I know I should be able to do the math myself but my brain is just fried right now. :)


-Dave

p.s. Unfortunately the screen cannot be moved without a HUGE effort since it is a curved screen mounted in a screenwall. Minor tilting of the screen should not be too much effort.

Can you help me figure out how much screen/projector tilt I'd need to use the HD81 in my theater?

Joe Morris wrote a calculator that will let you try all kind of "what if" scenarios. It will tell you the tilt angle you need. This is the link for it.

http://www.avsforum.com/avs-vb/attachment.php?attachmentid=61175

Joe

Joe Morris wrote a calculator that will let you try all kind of "what if" scenarios. It will tell you the tilt angle you need.
Thanks, Joe. It looks like the calculator will only compute the angle assuming your lens is aligned with the top edge of the screen. Given that I have a partial offset I was able to make some minor modifications to the spreadsheet and figured that I need a 2.3 degree tilt. Some additional computations led me to the final number I was looking for: I will need to either pull forward the top edge (or push back the bottom edge) just a fraction over 2" to achieve my tilt.

Should be very subtle and I'm totally willing to live with that.

Thanks!


-Dave

Joe Morris wrote a calculator that will let you try all kind of "what if" scenarios. It will tell you the tilt angle you need. This is the link for it.

http://www.avsforum.com/avs-vb/attachment.php?attachmentid=61175

Joe
However it is not quite accurate. To eliminate all of the offset you will need the following tilt at the widest angle (shortest throw):

arctan of (9/16*0.362/1.8) = 6.45 degrees

and for the telephoto (long throw) end of the zoom:

arctan of (9/16*0.362/2.2) = 5.29 degrees

These values are independent of screen size. It is also important to note that these are just aproximations. You can only get a ballpark estimate of offset as you plan to design your HT. You can't build everything and then slap the projector in place and hope everything works out. The adjustments will need some tweaking. Just remember that in this situation you can remove most of the offset by tilting the projector.

My best advice was from post #999:

Both need to be tilted the same number of degrees. You don't need to lock into hard numbers at this point. You just want to get in the ball park.

When it comes time for your ceiling installation, tilt the projector up and set the zoom such that the bottom of the image fits perfectly on the bottom of your screen. Your image should have a slight trapezoid keystone shape at this point. Now tilt the top the screen forward slightly until the keystoning goes away. Viola! you're done and never had to get out the protractor.

My illustration was just to give you an idea of how it works and how you can make the HD81 work with low ceiling and still have reasonably large screens. Bottomline: if you can tilt your screen, the HD81's offset won't be that big of a problem. Honestly, I think screen tilting can actually be somewhat beneficial in terms of image quality over just keeping the screen flat. I wouldn't hesitate to recommend screen tilting to people who have 9 foot or higher ceilings; if the audience is looking slightly up, the screen will look best tilted slightly forward.

-Mr. Wigggles

Hi Dave,

If you need to be able to explore more scenarios besides having the lens level with the top of the screen, send me a private message & I can either help you more or get you the formulas & drawings I worked out.

Joe

Oops - never mind. It look like Mr. Wiggles just provided lots of info. Well, let me know if there is anything more I can provide.

Tzung or Wing,

If you ship me a projector, I can make an installation video for you to show everyone these installation tricks in action. The tricks aren't hard but if a picture is worth a thousand words, imagine what a video could do.

:)

-Mr. Wigggles

If you ship me a projector, I can make an installation video for you to show everyone these installation tricks in action.

I'll arm-wrestle you for it. :p

Joe

What are the maximum and minimum distances you should be seated from the screen before the detail on 1920x1080 material is lost and 720p becomes the more sensible option? Or, rather, what is the threshold between 1080p and 720p as far as viewing distance, where one type of projector makes sense over the other?

I just realized my screen has to be smaller in order for the case to fit in the are of my room where it needs to be placed (the steel beam in the soffit is closer to the screen than I originally thought). This means I can get the HD81 again... ROFL. It also means that 1080p might no longer be a viable projector for me considering how far from the screen I will be compared to the new screen width... *cries*

I think you have to be within 2 X screen widths to be able to resolve 1080, and after that either display will look about the same (all else being equal).

Gary

What are the maximum and minimum distances you should be seated from the screen before the detail on 1920x1080 material is lost and 720p becomes the more sensible option? Or, rather, what is the threshold between 1080p and 720p as far as viewing distance, where one type of projector makes sense over the other?

QC, not sure I can "really" answer you question as I think there is a great deal of "preference" involved here.

However, I can tell you that when I viewed the HD81 at CES in January I could not see any pixel structure until I was within 4' of a pretty large screen (cannot remember exact dimensions, but I think it was in the 135->142" size).

I believe Mr. Wiggles mentioned earlier that he thought you would need to sit at about 1.2 of screen width to really get the full benefit of the 1080p.

I know its a big no no but with the higher resolution and the high end scaler how much distortion would a slight keystone adjustment make?

What are the maximum and minimum distances you should be seated from the screen before the detail on 1920x1080 material is lost and 720p becomes the more sensible option? Or, rather, what is the threshold between 1080p and 720p as far as viewing distance, where one type of projector makes sense over the other?

I'm in the process of experimenting with Front Projection in my home for the first time, using an Infocus IN76 (720p dlp) onto a 120"diag screen. From my viewing distance of 12.5 ft (1.43 x screen width) I can definitely see the screen door effect. So from this distance, for me, 1080p would definitely be an improvement and worth it (to me).

If you ship me a projector, I can make an installation video for you to show everyone these installation tricks in action. The tricks aren't hard but if a picture is worth a thousand words, imagine what a video could do.How many weeks/months would it take you to make the video? :)

--Darin