Optoma H72 - Page 10 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #271 of 2915 Old 01-29-2006, 06:34 PM
Advanced Member
 
Tnedator's Avatar
 
Join Date: Jul 2001
Posts: 523
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked: 16
I am a bit confused on the offset. I want to mount the projector 13' 6" from a 118" screen. Anyone know how much above the top of the screen the projector would have to be?
Tnedator is online now  
Sponsored Links
Advertisement
 
post #272 of 2915 Old 01-29-2006, 07:23 PM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Tnedator View Post

I am a bit confused on the offset. I want to mount the projector 13' 6" from a 118" screen. Anyone know how much above the top of the screen the projector would have to be?

Tned,

Per user manual -- 162" * tan(6.52) = 18.51".

Top of your screen is going to be 18.51 below the center of the lens.
Screen size makes no difference.

Davie.
eclipse98 is offline  
post #273 of 2915 Old 01-29-2006, 08:12 PM
AVS Special Member
 
bubbawilly's Avatar
 
Join Date: Jan 2003
Location: Colorado
Posts: 2,716
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Please explain your calculation.
bubbawilly is offline  
post #274 of 2915 Old 01-29-2006, 08:32 PM
Advanced Member
 
rsmith4321's Avatar
 
Join Date: Mar 2004
Posts: 530
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I really liked this PJ, but the offset sounds so high I don't know how many of us will be able to use it. Why can't they just be more reasonable with the offset. I haven't seen one person yet that was glad for a huge offset, so why do they do it?
rsmith4321 is offline  
post #275 of 2915 Old 01-29-2006, 11:28 PM
AVS Special Member
 
fleaman's Avatar
 
Join Date: Mar 2003
Location: Los Angeles
Posts: 4,577
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 83
Quote:
Originally Posted by rsmith4321 View Post

I really liked this PJ, but the offset sounds so high I don't know how many of us will be able to use it. Why can't they just be more reasonable with the offset. I haven't seen one person yet that was glad for a huge offset, so why do they do it?

I'm glad.

Fleaman
fleaman is offline  
post #276 of 2915 Old 01-29-2006, 11:28 PM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by bubbawilly View Post

Please explain your calculation.

Page 16 of the user manual says:

H' (offset) = L (distance from PJ to screen) * tan (6.52)

L: 13"6' = 162 inches
tan(6.52) = 0.1142

H' = 162" * 0.1142 = 18.51"

As I said, screen size makes no difference in offset.

Thanks, Davie.
eclipse98 is offline  
post #277 of 2915 Old 01-29-2006, 11:35 PM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by rsmith4321 View Post

I really liked this PJ, but the offset sounds so high I don't know how many of us will be able to use it. Why can't they just be more reasonable with the offset. I haven't seen one person yet that was glad for a huge offset, so why do they do it?

I agree, smaller offset would be better -- even with 8.5 feet ceiling in my basement I can't project to bigger than 110 inch screen - anything bigger will force me move screen too low -- good thing is that my viewing distance is 14 feet so I guess 110 inch will work fine.
eclipse98 is offline  
post #278 of 2915 Old 01-29-2006, 11:36 PM
AVS Special Member
 
fleaman's Avatar
 
Join Date: Mar 2003
Location: Los Angeles
Posts: 4,577
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 83
Quote:
Originally Posted by rsmith4321 View Post

I really liked this PJ, but the offset sounds so high I don't know how many of us will be able to use it. Why can't they just be more reasonable with the offset. I haven't seen one person yet that was glad for a huge offset, so why do they do it?

It seems the HD72 has a similar offset as the H30 (depending on firmware) and the H31, 4805....

And I believe you had at least 2 of these projectors?

Fleaman
fleaman is offline  
post #279 of 2915 Old 01-29-2006, 11:49 PM
Senior Member
 
myapplebuddy's Avatar
 
Join Date: Sep 2002
Location: North Idaho
Posts: 307
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by rsmith4321 View Post

I really liked this PJ, but the offset sounds so high I don't know how many of us will be able to use it. Why can't they just be more reasonable with the offset. I haven't seen one person yet that was glad for a huge offset, so why do they do it?

I'm glad too - I have a high vaulted ceiling in my living room.
myapplebuddy is offline  
post #280 of 2915 Old 01-30-2006, 05:26 AM
Advanced Member
 
Tnedator's Avatar
 
Join Date: Jul 2001
Posts: 523
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked: 16
Quote:
Originally Posted by eclipse98 View Post

Tned,

Per user manual -- 162" * tan(6.52) = 18.51".

Top of your screen is going to be 18.51 below the center of the lens.
Screen size makes no difference.

Davie.

Ok, thanks. That's what I was afraid, I can't handle that much offset.
Tnedator is online now  
post #281 of 2915 Old 01-30-2006, 06:30 AM
AVS Special Member
 
price3's Avatar
 
Join Date: Jan 2003
Location: Clemson, SC
Posts: 1,181
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Ugh, my screen top is like 10 inches from the ceiling at most, I really wanted one of these.
price3 is offline  
post #282 of 2915 Old 01-30-2006, 06:56 AM
SCM
Senior Member
 
SCM's Avatar
 
Join Date: Dec 2001
Location: Birmingham, AL
Posts: 334
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by eclipse98 View Post

Page 16 of the user manual says:

H' (offset) = L (distance from PJ to screen) * tan (6.52)

L: 13"6' = 162 inches
tan(6.52) = 0.1142

H' = 162" * 0.1142 = 18.51"

As I said, screen size makes no difference in offset.

Thanks, Davie.

Davie,

But isn't "L" directly related to screen size? I know that zoom will give you some play with this, but at the same zoom, that larger the screen size, the further back the projector must be set. This gives a larger "L" value and a larger offset. I am not a math major, so am I missing something?

SCM is offline  
post #283 of 2915 Old 01-30-2006, 07:07 AM
AVS Special Member
 
bubbawilly's Avatar
 
Join Date: Jan 2003
Location: Colorado
Posts: 2,716
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by eclipse98 View Post


As I said, screen size makes no difference in offset.

It does, it just isn't used in this calculation. Optoma must have put the math geeks in charge of coming up with an offset formula. Using screen size would have been too easy, so why not put that math major to good use and throw in a tangent. Where else do you get to use one?

The size of the screen determines throw distance, and vice versa. Neither measurement is mutually exclusive. Therefore, the product of the equation has as much to do with screen size as it does throw distance. You can't get a 80" diagonal image at a 13.5' throw, just like you can't get a 118" image from a 10' throw.

The resultant offset is still ~32%.
bubbawilly is offline  
post #284 of 2915 Old 01-30-2006, 09:38 AM
AVS Special Member
 
JeffKB's Avatar
 
Join Date: Feb 2003
Location: Albany, NY
Posts: 1,922
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by fleaman View Post

It seems the HD72 has a similar offset as the H30 (depending on firmware) and the H31, 4805....

And I believe you had at least 2 of these projectors?

Although the question was not directed to me, just to chime in:

A 27% or 32% offset makes sense on low resolution PJs like those, since most will be using a smaller screen due to viewing angle issues (i.e. needing to maintain about 2x width). For smaller screens (say 92"), those offsets make sense and work out well for most people. But the problem is that it's quite common to want to increase your screen size when you trade up in resolution. That's why there's more complaints about the offset with this PJ vs the H30 or 4805. What was the perfect offset at 92" is now too steep when you want to trade up to 106" or 110".

I'm planning on getting the IF IN76 for my upgrade, but the H72 is a legitimate backup plan for me in case the IN76 stays $1K higher or has initial issues. The offset is the major stumbling block. Oh well, I guess I should remember that when I bought my 4805 a scant 18 months ago, the cheapest 720p DLP was streeting for over 4 grand. If this PJ was available back than for $500 more than what I paid for my 4805, I could have cared less about the offset - I would have MADE it work, one way or the other!
JeffKB is offline  
post #285 of 2915 Old 01-30-2006, 10:25 AM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by SCM View Post

But isn't "L" directly related to screen size? I know that zoom will give you some play with this, but at the same zoom, that larger the screen size, the further back the projector must be set. This gives a larger "L" value and a larger offset. I am not a math major, so am I missing something?


SCM, It would make a difference if the question was asked differently, e.g. "I have 118 " screen, with 1.0 zoom how much below the center of the lens will I need to mount the screen ?"

In this case we still would calculate L based on zoom and screen size and then calculate offset based on L. Look at it this way -- at particular L (162 for example), the top of the screen is always going to be 18.5" below the center of the lens (at least that what their manual says). I think what causes confusion is percent offset relative to screen height.

If you look at the same calc with different zoom, at 162 inches you can throw either 99" or 119" diagonal image (48" & 58" high respectively). Now if you calculate percentage offset, it will be:

18.51 / 48 = 38.5%
18.51 / 58 = 31.9%

Having said that, offset in inches is going to be the same (18.51) from 162" throw distance no matter if you project to 99" or 119" screen. The bottom of the image will simply move 10" lower for bigger screen, but the top will be the same.

HTH, Davie.
eclipse98 is offline  
post #286 of 2915 Old 01-30-2006, 10:59 AM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by bubbawilly View Post

It does, it just isn't used in this calculation. Optoma must have put the math geeks in charge of coming up with an offset formula. Using screen size would have been too easy, so why not put that math major to good use and throw in a tangent. Where else do you get to use one?

The size of the screen determines throw distance, and vice versa. Neither measurement is mutually exclusive. Therefore, the product of the equation has as much to do with screen size as it does throw distance. You can't get a 80" diagonal image at a 13.5' throw, just like you can't get a 118" image from a 10' throw.

The resultant offset is still ~32%.

Bubbawilly, I agree that screen size will make a difference in the calculation if the throw distance is not set. This way you will still need to calculate L and based on that calculate H'.

However, the question in the post specifically mentioned fixed throw distance of 13"6' and at this throw distance offset is always going to be 18.51" no matter how big the image is going to be projected (99" or 119").

Davie.
eclipse98 is offline  
post #287 of 2915 Old 01-30-2006, 11:08 AM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by myapplebuddy View Post

I'll be using my HD72 with a Carada Criterion 96" screen with their Brilliant White material. I think it would be in your price range, even at the size you want to get. I read a comparison a while ago that said the Carada Brilliant White material is similar to the Stewart Studiotek 130 material. My dad uses a Carada Brilliant White screen with his Optoma H57 and it looks amazing. Grey screens are mostly good for improving blacks and for rejecting ambient light. The HD72 should have great blacks so unless you're using it with lots of ambient light, you should be fine with a white screen. The Carada screens are an incredible value for what you get.

Myapplebuddy, thanks for your screen suggestion -- I've read some reviews on Carada and they all are very positive. What I also like about them is the 30 day money back guarantee, so I've got nothing to lose except S&H charges. All other screen manufacturers I've been looking at (or their resellers) do not give you this option.

Thanks, Davie.
eclipse98 is offline  
post #288 of 2915 Old 01-30-2006, 11:21 AM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by MikeSer View Post

Eclipse98,

I am also using Carada's Brilliant White Criterion screen. but smaller in size than myapplebuddy's screen.
The material is just a thin milky white vinyl (or something like that).
I thought the screen "material" was pretty "low tech" when I bought it, but it does provide a very uniform and smooth picture.
The frame is very well made and very sturdy.

You can order the screen with a gray material, but if you don't like it ,you will end up paying for the material twice (once for gray and once for white).
Gray material will provide better "blacks," but it will make the whites and bright colors somewhat muted.

I would not recommend spending a lot of money on a white or gray screen, because you may decide to buy black screen when it becomes more affordable.

Mike


MikeSer, I don't think I will end up paying for material twice since Carada give you 30 day money back guarantee, so I can just swap one for another if I don't like it.

Also, their prices seem very reasonable compared to other screen manufactures and I don't feel like spending a lot of money for it -- seems to be a good value product.

Thanks, Davie.
eclipse98 is offline  
post #289 of 2915 Old 01-31-2006, 12:18 AM
Senior Member
 
TimB's Avatar
 
Join Date: Dec 2001
Location: Cary NC
Posts: 298
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Copied from post #164 in this thread.
Quote:


I hate to belabor this, but since it continues to come up on every page ...

The offset is a red herring for people using fixed screens. As others have said, in this and other threads, all you need do is tilt the projector up a bit, and shim out the top of the screen a bit.

Think of the entire projector and screen as rigidly linked - imagine tie-rods going from top and bottom of screen to top and bottom of projector. Now, just rotate the projector up until the top of the screen is where you want it. With a 15 or 20 foot radius, moving the screen up a foot or two is only a few degrees of rotation, and the top of the screen only comes out a couple inches from the wall.

Of course, drop down screens hang plumb, so this is still a problem for them (unless they could fashion a track that would pull the screen bottom toward the wall a couple inches)

TimB is offline  
post #290 of 2915 Old 01-31-2006, 04:25 AM
Senior Member
 
mooney's Avatar
 
Join Date: Feb 2004
Location: Austin TX, Pagosa Springs,CO
Posts: 254
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
For those with OFFSET concerns

There are 3 projectors using the new TI chip (Mits HD3000, Optoma HD72 and the InFocus IN76) and the sleeper in this is the InFocus IN76 as Jeff mentioned.

The offset is about 15.6% vs 32% or so for the HD72.

The offset and the good support and reputation of IF may be worth a few 100's more $$ than the Optoma. My guess is that the price difference will be way less than some have guessed.

Bob
mooney is offline  
post #291 of 2915 Old 01-31-2006, 06:42 AM
AVS Special Member
 
bubbawilly's Avatar
 
Join Date: Jan 2003
Location: Colorado
Posts: 2,716
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by TimB View Post

Copied from post #164 in this thread.


I'm sure that everyone has read this, yet there is still great concern over the fairly significant offset of the HD72. Obviously, most folks don't consider permanently tilting their screen an acceptable option.
bubbawilly is offline  
post #292 of 2915 Old 01-31-2006, 06:46 AM
AVS Special Member
 
bubbawilly's Avatar
 
Join Date: Jan 2003
Location: Colorado
Posts: 2,716
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by mooney View Post

For those with OFFSET concerns

There are 3 projectors using the new TI chip (Mits HD3000, Optoma HD72 and the InFocus IN76) and the sleeper in this is the InFocus IN76 as Jeff mentioned.

The offset is about 15.6% vs 32% or so for the HD72.

The offset and the good support and reputation of IF may be worth a few 100's more $$ than the Optoma. My guess is that the price difference will be way less than some have guessed.

The IN76 will have an MSRP of $2999, just like the Optoma. It will depend on the sales channel as to what the street price is. Like you mentioned, the 16% offset, and the more flexible zoom range of the 76 will make it worth the extra month's wait for many.
bubbawilly is offline  
post #293 of 2915 Old 01-31-2006, 09:30 AM
AVS Special Member
 
JeffKB's Avatar
 
Join Date: Feb 2003
Location: Albany, NY
Posts: 1,922
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Regarding tilting your screen to account for the offset, that will work, but it is not the universal solution for all nor does it mean that offset is a red herring. In some cases the "slight tilt" won't be that slight at all. Based on the degree of tilt you need, you may or may not find that solution appealing.

The InFocus SP5700 has about the same offset as the H72, and the Excel screen calculator for the SP5700 will calculate the screen tilt needed to correct for a projector tilt (no doubt InFocus received complaints about the 32% offset just like Optoma currently is, hence the need to include the screen tilt calculator. Note that the SP5700's current version on the IF website does not contain this, but I have an older version that does. I'll try to find that version somewhere online and link to it later). Tilt varies by throw distance, and since the H72's farthest throw is close to the SP5700's shortest throw, you should use the SP5700 short throw figures when determining tilt.

EDIT- here's the SP5700 screen calculator:
http://www.infocus.com/service/sp570...%20english.xls

Here's an example that I don't think is going to be that atypical:

Your HT is in a basement with a ceiling height of 7'5". You want a 110" screen and you plan on mounting the H72 at the far end of its throw range. That means the offset is 38% (that assumes that the manual is correct and offset is dependant on throw distance and varies from 32% to 38% of screen height).

If you run the math, that puts the bottom of your screen at:

89" ceiling height, minus 5" mount drop, minus 20.5" offset drop, minus 54" screen height, equals 9.5 (call it 10") above your floor.

If you want to achieve the "eyes 33% up from the bottom of your screen" rule, you need to get the bottom of your screen up to 24" off the floor (42" average eye height - 18" = 24"). You need to raise your image up 14".

If you plug the numbers into the SP5700 calculator and use the short throw figures, you'll see that you need to tilt the projector up around 4.5 degrees and tilt the top of your screen out from the wall by between 4 and 5 inches.

I can only speak for myself, but I don't find that very appealing at all. With that degree of tilt I'd be willing to bet that you could tell that your screen was tilted while watching a movie, and I would find that distracting.

I will say this however - although IMO the offset is less than ideal, I think most people who say they can't consider the H72 because of it really COULD get it to work if they are willing to accept some compromises. You could tilt the screen, you could tilt the projector and then mask off the trapezoidal part of the image left and right (focus uniformity may suffer however), or you could simply accept the fact that the image is lower on the wall then where you'd like it. Of course, not everyone will find those compromises acceptable, and if that's the case, the offset would eliminate this projector from consideration for some.

I will now officially stop harping on the offset and move on.
JeffKB is offline  
post #294 of 2915 Old 01-31-2006, 09:54 AM
Senior Member
 
FlyingGimp's Avatar
 
Join Date: Oct 2003
Posts: 399
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by mooney View Post

There are 3 projectors using the new TI chip (Mits HD3000, Optoma HD72 and the InFocus IN76) and the sleeper in this is the InFocus IN76 as Jeff mentioned.

I mostly wrote off the IN76 when I read it does not have the new DDP3020 DMD controller. The DDP3020 is the most likely reason the HC3000 shows good improvement on temporal dithering artifacts. See the cinehome review , section 3.8.

Temporal dithering artifacts drive me nuts - I see them constantly in gaming when I spin around. So for me I'll try whatever I can to fit an HC3000 or HD72 into my room over the IN76. Of course I see temporal dithering infrequently in movies or TV, so for non-gamers it's probably not as big an issue. And there's the side note that, of the new breed of DLPs, if the IN76 offset is the only one that will fit in your room, it would certainly be at the top on my list. At least until we get more info on the Sharp XV-Z3000.
FlyingGimp is offline  
post #295 of 2915 Old 01-31-2006, 10:27 AM
Senior Member
 
gkanders's Avatar
 
Join Date: Apr 2002
Location: Lafayette, CO
Posts: 371
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
One other point about the IN76. The extra rows of pixels are permanently masked off. So if you like the idea of watching 4:3 material at 1024x768, it won't work as well for you. Of course, if you only want to watch 16:9 or 2.35:1 content, it's a non-issue, and may even be an advantage, since you won't have to worry as much (probably) about masking.
gkanders is offline  
post #296 of 2915 Old 01-31-2006, 11:25 AM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by bubbawilly View Post

The IN76 will have an MSRP of $2999, just like the Optoma. It will depend on the sales channel as to what the street price is. Like you mentioned, the 16% offset, and the more flexible zoom range of the 76 will make it worth the extra month's wait for many.

I think HD72 has MSRP $3999 (at least projector central says so). It will be very interesting to so the street price for IN76 with much lower MSRP and not as good warranty (just 1 year) -- I think they should be very close to HD72 street price to be able to compete. I already see some of LCD PJs "lowering" their prices to stay competitive -- Panasonic just increased their rebate to $400 for AE900
eclipse98 is offline  
post #297 of 2915 Old 01-31-2006, 11:41 AM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by mooney View Post

For those with OFFSET concerns

There are 3 projectors using the new TI chip (Mits HD3000, Optoma HD72 and the InFocus IN76) and the sleeper in this is the InFocus IN76 as Jeff mentioned.

The offset is about 15.6% vs 32% or so for the HD72.

The offset and the good support and reputation of IF may be worth a few 100's more $$ than the Optoma. My guess is that the price difference will be way less than some have guessed.

For whatever it's worth there is another interesting factor influencing offset -- aspect ratio. Since most movies are presented in 1:1.85 and 1:2.35 aspect ratio, for those of us who plan on watching mostly movies that gives some extra inches to play with.

If you take 106" diagonal screen in 16:9 (1:1.78 aspect) screen dimensions will be 92" x 52".

When you watch 1.85 / 2.35 content image height will decrease to 49.73" and 39.14" respectively -- that is extra 2" and whopping 12" to play with. If you digitally shift image to the top of the screen and mask the bottom black bar that can make heck of a difference.

Of course it will be useless for 16:9 or 3:4 aspect, but then again, depending on how much of this material you're going to watch may make you re-think offset issue.

Davie.
eclipse98 is offline  
post #298 of 2915 Old 01-31-2006, 12:13 PM
Advanced Member
 
jandawil's Avatar
 
Join Date: Oct 2005
Location: So Cal (High Desert)
Posts: 844
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I am really struggling between the H72 and the Panny 900u. Both are in my price range (although the rebates from Panasonic are enticing). My concern with Optoma of course is the offset. It may not be THAT bad in my case though. My ceiling is 99" high and my desired screen will be 102" X 57". Based on my math here the offset will be about 18.5" (using 32% of the screen height). Add the 5" for lense from ceiling and the the picture will be 23.5" from the ceiling and 18.5" off the ground (23.5+57=80.5 99-80.5=18.5") Using the desired screen placement of 1/3 below eye level that would place the desired screen height at 22" (assuming 39" eye level) Soooo I am only about 4" off. If I were to tilt the PJ to get the desired height up to 22 or 23" (4 or 5" tilt) how much would this effect the image and how far should the screen be tilted out to compensate for it?? I could not make sence out of the excel calculator. Would it be noticeable??

jandawil is offline  
post #299 of 2915 Old 01-31-2006, 05:06 PM
Senior Member
 
MikeSer's Avatar
 
Join Date: Apr 2003
Location: Virginia
Posts: 476
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by JeffKB View Post

If you want to achieve the "eyes 33% up from the bottom of your screen" rule...

Why would I feel obligated to follow some obscure rule???
My screen is low off the floor (less than 16"), because that's the way I like it.
It is low, because in my particular predicament I cannot use a recliner.
With a recliner seating, it would make sense to elevate the screen to a height that "feels right."

OTOH, I agree that 10" is too low. Let's not forget that we are discussing a "budget" PJ.
It's VO value is probably strongly influenced by a desktop configuration, as opposed to a ceiling-mount configuration.

Mike
MikeSer is offline  
post #300 of 2915 Old 01-31-2006, 05:30 PM
Senior Member
 
eclipse98's Avatar
 
Join Date: Dec 2005
Location: Denver, CO
Posts: 441
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by MikeSer View Post

Why would I feel obligated to follow some obscure rule???

I agree with Mike,

What's important is how you feel about your screen location vs. some rule that nobody knows where it came from. I think it's not a rule, rather some general guidelines to assist you with your screen placement, but the final judge is you.

Even following this "rule" does it make so much difference if it's off by 4 inches ? 1-2 feet maybe, but not 4 inches. Also, remember last time you went to the movies -- did you follow this 33% rule or was it way off -- I bet you still enjoyed the movie.

Davie.
eclipse98 is offline  
Reply Digital Projectors - Under $3,000 USD MSRP

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off