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post #91 of 2404 Old 02-12-2005, 07:09 PM
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Quote:
Originally posted by guitarman
Scott my distance will be 14' and I aim the meter at the lens correct? Thx for the tip on the backlight. [/b]

That is correct. At the screen. When reading LUX (or Fc), it isn't going to change too much (vs 1/2" back with screen retracted) for this purpose if you just put the sensor's back to the screen. Sensor's back to screen can be our common point. Back to the screen would be my preferred measurment for the comparitive LUX/Fc.

So what I'd like to know is:

1. Lux (or Fc) reading from your Extech meter with meter sensor's back to screen,
2. the 16:9 image width (92" per your previous post)
3. Distance to screen (14' per your previous post)

And yes, of course at night. I too, have to wait to night for this meas. due to windows.

Thanks Tom! Scott
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post #92 of 2404 Old 02-12-2005, 11:13 PM - Thread Starter
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Hi Scott, sri I'm late but like I said I party at night.

Ok 92" wide image 14' away 100IRE total dark no screen, centered light meter facing the PJ, 19.95 ft-candlesl. Not bad heh?

Lux is 18.55

3.60 ft candles at 3 feet, centered up.

Told you the H79 is bright.

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post #93 of 2404 Old 02-12-2005, 11:20 PM
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Quote:
Originally posted by darinp2
Thanks. I'm not sure about the TI chip converting it back to 60Hz since the Sharp 11k/12k will take this and passes the extremely difficult opening of "Shakespeare in Love". In this case the Sharp isn't doing the 3:2 pulldown though. That is done externally and then fed in as 48Hz. Either with a PC or with an iScan HD. Then it is up to me to switch the input to 60Hz for video material.

--Darin

I made a custom resolution on my momitsu 1280x720 at 48hz. My Optoma H77 takes it an indicate that it's feeding signal is in fact 1280x720 at 48hz.
I watch a few movies and it's seem fluid at that resolution. I don't have "Shakepeare in love" in my DVD collection. Any other title and scene I can experience with?
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post #94 of 2404 Old 02-12-2005, 11:26 PM - Thread Starter
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Hey, today I received a Bravo D2, just used 720p and image looks clean with no EE, not like the Oppo I was trying. Very nice DVD image - No hang ups either. Solid machine/ recommended.

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post #95 of 2404 Old 02-12-2005, 11:52 PM
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Quote:
Originally posted by bgosselin
I made a custom resolution on my momitsu 1280x720 at 48hz. My Optoma H77 takes it an indicate that it's feeding signal is in fact 1280x720 at 48hz.
I watch a few movies and it's seem fluid at that resolution. I don't have "Shakepeare in love" in my DVD collection. Any other title and scene I can experience with?

I have a Momitsu and didn't even think of making a custom 1280x720@48 from it for my 11k. I'm not sure why not. I'll have to try that.

I'm trying to think of good test scenes. I know some people have mentioned Titanic where they pan across showing the whole boat. There are some scenes from the extended version of "Return of the King" I was looking at where they pan up to show the city on the hill. I know there is a spot in the last chapter of the first disk where the Steward looks down over the edge of the city to see the big army in front of them, but that is a quick one. If you have "The Matrix" just after Trinity runs to the phone about 10 minutes in there is a pan up through some rubbish to a telephone laying off the hook and this one is a little jumpy at 60Hz on my 11k, but not at 48Hz (from my PC). I'm going to go try the HD version from HBO (Comcast) to see how well it plays back at 48Hz.

More will probably come to mind later if you don't have any of those.
Quote:
Originally posted by guitarman
Lux is 18.55

3.60 ft candles at 3 feet, centered up.

Told you the H79 is bright.

Are you sure that lux is right? That doesn't sound very bright. Is it off by a factor of 10?

--Darin

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post #96 of 2404 Old 02-13-2005, 12:28 AM - Thread Starter
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Don't know how great the meter is but those are the figures it brought up facing the PJ 14' away. I'm still feeling my way through using the meter though. What kind of numbers should it have read? Are th Ftl's ok?

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post #97 of 2404 Old 02-13-2005, 03:29 AM
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Quote:
Originally posted by bgosselin
I made a custom resolution on my momitsu 1280x720 at 48hz. My Optoma H77 takes it an indicate that it's feeding signal is in fact 1280x720 at 48hz.
I watch a few movies and it's seem fluid at that resolution. I don't have "Shakepeare in love" in my DVD collection. Any other title and scene I can experience with?

I also did the same test with the dvdo hd+ juttertest test again with 1280x720x48 output and it moved smooth. You also hear the colorwheel step down and the cooling fans change speed (they are linked).

Daniel.

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post #98 of 2404 Old 02-13-2005, 04:27 AM
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Tom,

That's about 1.7 ft lamberts. There are 3 or 4 ranges on the light meter, try to use one that will register somewhere in the middle of the range. One of them has a x10 factor to apply, so you'll probably want the one before it.

To convert your Lux to Lumens, multiply by 3.072. If we all talk in lumens then we're comparing equaly and to the manufacturers light output. The conversion number will change depending on the screen size. My 84inch wide screen needs 2.561 to do the conversion.

1lux = 1 lumen per square meter, so just convert your screen area into square meters and multiply it by the lux number on you meter. We need square feet for ft lamberts though.

If you calculate your screen area in square feet, you can divide it by 10.764 to come to square meters if that makes it easier.

Gary.

Quote:
Originally Posted by elmalloc
Who says Cameron is "right" and why do we care about him so much - lol!

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post #99 of 2404 Old 02-13-2005, 06:39 AM
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Quote:
Originally posted by bgosselin
I made a custom resolution on my momitsu 1280x720 at 48hz. My Optoma H77 takes it an indicate that it's feeding signal is in fact 1280x720 at 48hz.
I watch a few movies and it's seem fluid at that resolution. I don't have "Shakepeare in love" in my DVD collection. Any other title and scene I can experience with?

I setup a custom resolution for my Momitsu after reading your message and tried this with the 11k. However, I forgot that when testing the Momitsu before I think we found that it basically stays in video mode. That is, I don't think it does the 3:2 pulldown required to get smooth playback at 48. I'll probably try to rent or buy "Shakespeare in Love" later to verify things a little more.
Quote:
Originally posted by danielo
I also did the same test with the dvdo hd+ juttertest test again with 1280x720x48 output and it moved smooth. You also hear the colorwheel step down and the cooling fans change speed (they are linked).

Thanks. That is good to hear. I wonder how much the colorwheel slows down. I believe that Dan Miller said that the S3 colorwheel spins at 3x for 48Hz (instead of the normal 2.5x for 60Hz). That would equate to 288Hz instead of 300Hz on the S3, so not a lot of drop. If they kept the spinning at 2.5x it would go to 240Hz. This is all with 2 sets of RGB on the wheels.

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post #100 of 2404 Old 02-13-2005, 08:57 AM
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Quote:
Originally posted by darinp2
I setup a custom resolution for my Momitsu after reading your message and tried this with the 11k. However, I forgot that when testing the Momitsu before I think we found that it basically stays in video mode. That is, I don't think it does the 3:2 pulldown required to get smooth playback at 48. I'll probably try to rent or buy "Shakespeare in Love" later to verify things a little more.

--Darin

I'm far from beeing an expert in deinterlacing. But I thought that setting the resolution to 48hz was to eliminate the need for 3:2 pulldown and replace it with 2:2.

I have the matrix. I will try that scene with trinity. Even if it's not smooth chance are that the momitsu is at fault. The H77 seems to sync at 48hz anyway. Danielo test is a better test.

Bruno
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post #101 of 2404 Old 02-13-2005, 09:01 AM
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Tom,
Are you making all of your adjustments in the normal H79 menu or in the service menu? Can you post your results so far (changes you made from OTB setup - maybe show original value vs. changed value)? I'm curious where most of your tweaking is going on and it certainly will be a good guide for other H79 owners. Thanks. SJ
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post #102 of 2404 Old 02-13-2005, 09:28 AM
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Quote:
Originally posted by Gary Lightfoot
[b]To convert your Lux to Lumens, multiply by 3.072. If we all talk in lumens then we're comparing equaly and to the manufacturers light output. The conversion number will change depending on the screen size. My 84inch wide screen needs 2.561 to do the conversion.

It may not be that straight forward IMO. I'm more interested in seeing raw fc (or Lux - metric) measurments and to know what the projector is set to display at what distance. i.e. 5fc @ 14' with PJ set at 100" diag screen size. Then we don't throw any conversion errors into the report.

Tom:

Gary is right. The range button on your meter will cycle through several ranges. You'll see the decimal point move and the x10 indicator come and go. Choose the range that will give the most decimal points. If the light is too bright the meter will display "L" I think saying it's range is exceeded, so back down one scale.

One thing that there is no doubt (in my mind) about it converting Luc to Fc, that's just SAE and metric units. To convert fc to Lux it's:
Lux = Fc * 10.76
Fc = Lux * .0929

So for my 300E measurments I had 5.69 Fc, and that = ~63 Lux

For your measurments, 19.95Fc @ 14' that woudl equal ~210 Lux at the same distance. And that would be very nice I think, even for a new bulb. If it dropped 50% with age it would still be double than what I measured.

So if you can, check your meter ranges via it's range button and give another shot to double check.

Thanks!
Scott
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post #103 of 2404 Old 02-13-2005, 10:07 AM
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Quote:
Originally posted by bgosselin
I far from beeing in expert in deinterlacing. But I thought that seeting the resolution to 48hz was to eliminate the need for 3:2 pulldown.

I have the matrix. I will try that scene with trinity. Even if it's not smooth chance are that the momitsu is at fault. The H77 seems to sync at 48hz anyway. Danielo test is a better test.

Bruno

Lets not forget i am using a pal model of the H77 and that needs to work at 50hz anyway so thats very close to 48hz. We can't be sure if it will work the same with all models because of this. Also i can't be 100% sure its doing 48hz internally just hear it go down from 60hz (on ntsc signals) to a lower speed if i put the hd+ to 48hz instead of 59.xx).

But my question is still should pal (or 48hz) not be easer for the system since it has (even with 8 segments) more time per segment (since the wheel is running alot slower). My question on mirror speed is also still open i claim that HD2+ and DC3 run the same mirror speed (fast track) anyone who has facts im wrong ?

Daniel.

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post #104 of 2404 Old 02-13-2005, 12:15 PM
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Quote:
Originally posted by bgosselin
I far from beeing in expert in deinterlacing. But I thought that seeting the resolution to 48hz was to eliminate the need for 3:2 pulldown and replace it with 2:2.

I think you're right. My point was really that if the Momitsu isn't looking at film flags it won't be able to do either. I remember during one test with an AVIA pattern that checks for how long it takes a player to switch between film mode and video mode, the Momitsu just seemed to stay in video mode the whole time.
Quote:
Originally posted by danielo
My question on mirror speed is also still open i claim that HD2+ and DC3 run the same mirror speed (fast track) anyone who has facts im wrong ?

I remember that a TI document somebody pointed to did claim that the mirrors are faster with DC3 than HD2+. I don't remember it saying how much faster though.

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post #105 of 2404 Old 02-13-2005, 12:57 PM
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Quote:
Originally posted by danielo
My question on mirror speed is also still open i claim that HD2+ and DC3 run the same mirror speed (fast track) anyone who has facts im wrong ?
Daniel.

Not to nitpick, but to my understanding both chips are HD2+, only the older version is a DC2 and the newer DC3. Darin's point is correct, according to much of the literature, there is a change in speed, although like him I cannot recall the difference. The point of my correction is just to avoid future confusion.

Cheers,
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post #106 of 2404 Old 02-13-2005, 02:34 PM
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Quote:
Originally posted by Raul GS
Not to nitpick, but to my understanding both chips are HD2+, only the older version is a DC2 and the newer DC3. Darin's point is correct, according to much of the literature, there is a change in speed, although like him I cannot recall the difference. The point of my correction is just to avoid future confusion.

Cheers,
Raul


Yeah sorry hd2+dc2 vs hd2+dc3 , If there is a document someone have it since all hints ive seen the new speed was added with hd2 to hd2+ but each time i see this higher speed for dc3 coming up and would like to read about it in some TI doc.

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post #107 of 2404 Old 02-13-2005, 05:03 PM
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Quote:


Originally posted by scotthorton

One thing that there is no doubt (in my mind) about it converting Luc to Fc, that's just SAE and metric units. To convert fc to Lux it's:
Lux = Fc * 10.76
Fc = Lux * .0929

Scott

Those are the conversions I have too, so we agree there.

As the numbers refer to square feet or square meters, you can also use screen area to round up the calculation, but it changes from screen to screen of course as the areas will vary. I mistakenly used my screen area conversion instead of yours at one point. I edited in the correction tho.

It would certainly be good to know exactly what size screen and distance the manufacturers use to obtain their numbers though.

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Originally Posted by elmalloc
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post #108 of 2404 Old 02-13-2005, 05:21 PM
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Quote:


Originally posted by Gary Lightfoot
It would certainly be good to know exactly what size screen and distance the manufacturers use to obtain their numbers though.

Why? If you mean it would be nice to know which end of the zoom range they use, then yes, that could be useful. Apart from that or having a smokey room, the lumens should come out the same. For some of the projectors with multiple lenses I know that the max lumens can be at different ends of the zoom between 2 different lenses. I think they generally use one spec per projector to keep things simple, instead of having a couple of specs per lens choice. I believe that Bob Williams said they use the minimum image size end of the zoom for spec measurement on their projectors.

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post #109 of 2404 Old 02-13-2005, 05:33 PM
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I only ask because it would be nice to replicate their numbers. As it is, I'm getting 40% less on my H77 which is not unusual I know, but it does make you wonder if you've made an error somwhere.

Gary.

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Originally Posted by elmalloc
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post #110 of 2404 Old 02-13-2005, 05:41 PM
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Quote:


Originally posted by Gary Lightfoot
I only ask because it would be nice to replicate their numbers. As it is, I'm getting 40% less on my H77 which is not unusual I know, but it does make you wonder if you've made an error somwhere.

Do you have the white peaking turned on? And the colors blown out? I bet that is what they do. I don't see anywhere that they claim D65 for their specs. I think that Yamaha is pretty explicit about stating that their specs are with the white peaking feature (leaving mirrors on during spoke time) turned on, although I wouldn't use or recommend using that feature in general.

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post #111 of 2404 Old 02-13-2005, 06:27 PM
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Gary

White peaking is responsible for doubling the contrast ratio and brightness on the Infocus SP7205. Silly thing is they market contrast with white peaking on, but D65 brightness with white peaking off (since it is brighter than anything else anyways!). I bet that is your missing measurement - since you already maxed RGB - white peaking will max out gamma. Optoma certainly does not market the D65 numbers.

Read the latest HTmag - reviews several $3K DLP/LCD - all off them are about half spec.
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post #112 of 2404 Old 02-13-2005, 06:42 PM
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Quote:


Originally posted by krasmuzik
White peaking is responsible for doubling the contrast ratio and brightness on the Infocus SP7205.

Doubling. Wow! The Sharp 11k isn't even close to that, or I could get 7000:1 on/off CR.
Quote:



Silly thing is they market contrast with white peaking on, but D65 brightness with white peaking off (since it is brighter than anything else anyways!).

The specs I see are 1100 ANSI lumens and 2200:1 on/off CR. Are you saying that the lumens are at D65 and it can do over 2000 ANSI lumens with white peaking on? Is the CR 1100:1 with the white peaking off? I'm a little bit confused about how your explanation matches up with their specs since I would be pretty surprised if they could do even close to 2000 lumens, even with white peaking. But I guess I had assumed that their projectors were capable of over 1000 lumens without white peaking (since I don't think any reviewer should be calibrating with white peaking on).

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post #113 of 2404 Old 02-13-2005, 06:59 PM
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Quote:
Originally posted by darinp2
Do you have the white peaking turned on? And the colors blown out? I bet that is what they do. I don't see anywhere that they claim D65 for their specs. I think that Yamaha is pretty explicit about stating that their specs are with the white peaking feature (leaving mirrors on during spoke time) turned on, although I wouldn't use or recommend using that feature in general.

--Darin

Can you explain to me what spoke time mean? In the Optoma H77 service menu there is a fonction call Spoke light on: choice are white,black,red,green,blue

Bruno
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post #114 of 2404 Old 02-13-2005, 07:10 PM
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Quote:


Originally posted by bgosselin
Can you explain to me what spoke time mean? In the Optoma H77 service menu there is a fonction call Spoke light on: choice are white,black,red,green,blue

I sometimes refer to spoke time as no-man's-land, but spoke time is more accepted.

I'm not sure what all those choices are, but basically if you picture a colorwheel you will see that there are transition points between the segments, like where red becomes green. The logic for the chips and mirrors aren't fast enough to follow that line as it passes across the chip, so in general all mirrors are turned off during this time, which is called the spoke time. However, one way to get more white is to leave all the mirrors on for pixels that are supposed to be white during the spoke time for all 3 primaries (assuming a 6 segment wheel). This adds red, green, and blue, so essentially white. However, it messes up the grayscale and normal images because whites get really bright, where other things don't. It can still be a good way to fight ambient light if your images are getting totally washed out though (like in a boardroom). Basically, it works like the white segment on a business DLP, but just using 3 spoke times to equal one white.

I'm guessing that "white" means blow out these whites by turning the mirrors on during this spoke time. "Black" is the normal mode for HT. The "red", "green", and "blue" probably have something to do with leaving the mirrors on more as only those segments are entered or left, but I'm not sure of the actually functionality that would be.

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post #115 of 2404 Old 02-13-2005, 07:16 PM
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darinp2

Indeed that is the case! Contrast number comes from (nearly) doubling brightness with white peaking. (Infocus is always brighter than spec at D65 - but I guess somebody decided 1K contrast would not fly!). Now you know why I was arguing for using it as a plasma simulator with the Vutec SilverStar - just turn on the white peaking!

This should not be surprising since it is based on their LP650 design which was 2500 Lumens and 800:1 contrast. The ScreenPlay version just lowers the brightness and ups the contrast.

ISF LUMENS
SP7205 1126 (spec is 880 in low lamp, no white peaking)

ISF ON/OFF CONTRAST
SP7205 1200 (spec is 2200:1 with white peaking, this is with it off)

The huge contrast jump from SP7200 to SP7205 was 40% DC2 engineering, 60% marketing. This is why I like the SP4805 so much - it's marketed numbers are honest all the way around 2K:1 with no white peaking. Beats many higher priced boxes - and kills in the $<2K category (though guitarman is claiming the H31 should reclaim with the DC2 now - we shall see!)

I can measure it again - maybe not quiet twice but close. I intend to watch HellBoy-HD with the SP7205 so should be swapping it back in.

That is why I say contrast is fiction anymore - either DLP gets it with the white peaking, or LCD gets it with an IRIS to improve blacks. In either case you have non-linear gamma and blown out color temps that are not flat.

I remember when I reviewed the SP5700 before I learned of the white peaking "feature" - I was getting 1800 lumens! The initial firmware white peaking defaulted to 100 - later firmwares brought it down to 0.

Bottom line is I think that Optoma is using both white peaking and cyan color temps and hot lamps to get the brightness/contrast they claim. Which is fine - I would use that bright mode in the daylight room.
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post #116 of 2404 Old 02-13-2005, 07:18 PM
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bgosselin

spoke time is the white peaking feature - mixing the RGB to increase brightness by using the wheel closer to the spokes to the point that for an instant some of the screen might be half red, some might be half green. Your brain will perceive it as whiter as the wheel revolves - just as it does the sequential RGB flashing. Looks like a neat service menu feature if they let you control that mixture! Say you calibrate for 80IRE and reds are drained at 100IRE - use the service menu to add some red peaking!
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post #117 of 2404 Old 02-13-2005, 10:25 PM - Thread Starter
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The H79 has white peak but don't use it.

Sri guys I'll get back into it but I was up in Sacramento today with my equip tuning up Craigs H76. End result was excellent for Craig. I brought up the H79 for him to see. The difference between the two was pretty close. In general Optoma has a great product. Nobody has to worry about their model not producing a top notch picture. H79 produced a similar color palate with blacks/contrast being a little more deep. Both PJ's looked more than excellent.

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post #118 of 2404 Old 02-14-2005, 06:05 AM
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Looks like we won't see the H79 here in the UK. See below.

Hi Jeff,

Have no plans in introducing the H79 in the UK, thats what I've been told anyway. I suspect we might see some thing by the end of the year. H80?

Regards
Stuart
-----Original Message-----
From: Jeff Paynter [mailtorojectors@eurobell.co.uk]
Sent: 09 February 2005 15:01
To: Stuart Acey
Subject: H79


Hi Stuart,

Will the H79 be coming to the UK ?

If so, do you have price and availability.

Thanks

Jeff

Jeff Paynter
Director
Horsham Hi-Fi & Home Cinema Ltd
Tel: 01403 272931
Mobile: 07890 390310
www.projectorsareus.com
projectors@eurobell.co.uk

Jeff Paynter
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post #119 of 2404 Old 02-14-2005, 10:13 AM
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Thanks so very much Tom for calibrating my H76! That was extremely kind of you. I really like the H79 picture too. The difference picture wise from the H76 - H 77 - H79 is incremental, but it is noticeable. Little better blacks, little smoother picture. You can't really go wrong with any of these pj IMO - it just depends on how much you want to spend!

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Yes, we sell Home Theater gear right here at AVS !!
JVC, Sony, Epson, DPI, SIM2, SV Sound, Martin Logan, RBH, and many more!
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post #120 of 2404 Old 02-14-2005, 10:18 AM
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Quote:


Originally posted by RTFM
Looks like we won't see the H79 here in the UK. See below.

Hi Jeff,

Have no plans in introducing the H79 in the UK, thats what I've been told anyway. I suspect we might see some thing by the end of the year. H80?

Regards
Stuart
-----Original Message-----
From: Jeff Paynter [mailtorojectors@eurobell.co.uk]
Sent: 09 February 2005 15:01
To: Stuart Acey
Subject: H79


Hi Stuart,

Will the H79 be coming to the UK ?

If so, do you have price and availability.

Thanks

Jeff

Jeff Paynter
Director
Horsham Hi-Fi & Home Cinema Ltd
Tel: 01403 272931
Mobile: 07890 390310
www.projectorsareus.com
projectors@eurobell.co.uk


Thats because it will be called the H77a last time i asked (ill ask again) planned for may. Same as the H31 that is called H30a.

Daniel.

for men to evolve we have to upgrade
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