Projector Offset - Why? - AVS Forum
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post #1 of 8 Old 08-17-2008, 04:49 PM - Thread Starter
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I'm planning my screen wall and I keep running into screen size limitations based on the projector's offset (I'm looking at an Optoma HD81 or HD806).

Front wall dimensions are 8' x 11.25' - a bit smaller than I'd like but it's what I have to work with.

This will be my first true theater and I want to make sure that I get the largest screen that the room will allow but factoring in the offset a 120" viewable 16:9 is almost dragging on the floor.

I did a quick rendering and it looks like a 106" is about the largest I can get away with... (Elite CineTension2 Acoustic Series)

Is there any way around the offset or do all projectors require about the same distance? I could live with the screen a bit higher than optimal but the sight-lines from the second row won't work with it too low.





I'd give my right arm to be ambidextrous!
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post #2 of 8 Old 08-17-2008, 05:02 PM
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How far back are your going to sitting? Most screen sizes are based upon viewing area based upon seating location in relationship to the screen. The large the screen, the further away you may have to sit in order to be able to view the entire screen. Kind of like sitting in the front row at the real theaters.
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post #3 of 8 Old 08-17-2008, 05:22 PM - Thread Starter
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First row eyeballs are about 10'6" back

I'd give my right arm to be ambidextrous!
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post #4 of 8 Old 08-17-2008, 06:25 PM
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There are many pj's with less, none, negative and variable offset. Just need to look around for a more suitable pj.

Rob
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post #5 of 8 Old 08-17-2008, 07:24 PM
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The solution I've read for the large offset projectors is to tilt the projector up then tilt the screen forward an inch or so to compensate for the keystoning that tilting the projector causes. From a seated position the screen is actually more perpendicular to your eyes.

There have been reports of theaters built with front false walls where the entire wall is tilted forward to further disguise the technique.
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post #6 of 8 Old 08-17-2008, 10:32 PM - Thread Starter
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Thanks guys.

Unfortunately tilting the screen isn't really an option with a motorized screen (unless I'm missing some cool new invention or DIY mod).
I need a screen that retracts or flips up so that we can use the LCD TV for more informal viewing (and to use while I save up the $ for the projector/screen/wall treatments/etc).
I got a smoking deal on it and bought the TV so ditching it isn't really an option (and my wife would kill me).
In retrospect the TV probably wasn't my best idea - in fact it was an afterthought but I already pulled the wire & convinced my wife...

Looks like I'll have to visit projector central and find another model/brand or "live with" the 106" screen.

The size of the screen isn't really what bothers me so much as the limitations it imposes on speaker placement - I either have to keep the speakers a bit too wide or move them behind a transparent screen and place them too close together. If I go with the 120" I can place them behind the viewing area and maintain the desired separation. I already own the speakers also so switching brands/models there would also be a last resort.


At least I haven't been Loganed yet!

I'd give my right arm to be ambidextrous!
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post #7 of 8 Old 08-18-2008, 05:12 AM
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Oh, yes, you have!

Even when you THINK you aren't, you are!

Tom Logan
Everytime I reply the thread ends
Need motivation? Get LOGANED
http://www.avsforum.com/avs-vb/showthread.php?t=1014847

An as-yet un-named theater designed by Big-WarrenP-BritInVA
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post #8 of 8 Old 08-18-2008, 08:57 AM - Thread Starter
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Quote:
Originally Posted by tlogan6797 View Post

Oh, yes, you have!

Even when you THINK you aren't, you are!

Damit!


He'll find you.
That's what he does.
That's all he does!
You can't stop him.
He'll wade through you, reach down your throat, and embarrass you in a public forum!

I'd give my right arm to be ambidextrous!
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