# Projector placement



## Guest (Apr 11, 2007)

I'm in early-theater build (just 95% done framing). I have a few constraints in my room, primarily an I-beam running across my room (parallel to the screen). My finished ceiling is going to be about 91" with the beam being finished off about 83". My screen size is most likely going to be 92". My viewing distance is going to be about 12', my wife and I are still working this out (furniture space/bar/walkways).

I'm concerned about a few things.
First...the I-beam limiting my projector choices. My instinct tells me to put the projector in front of the I-beam. This allows me to put it all the way up against the ceiling and have it out of the way. This puts my throw distance at about 10'6" max (assuming this distance is measured from the lens surface). I can move the projector back, but this would force me to mount it lower. This would affect viewing from the bar behind and make it overall just less visually appealing.
Second...if I leave the projector in front of me (about 2-2.5feet), is this going to bother me (light spill from the projector)? I have an idea about this..I could box in the projector and use the "channel" of the boxed in I-beam to carry the heated air elsewhere (maybe with a fan). Or...there is an AC vent (sucker...never can remember supply or return) just above the projector...I could vent my "hushbox" into there.

Finally...am I going to have any problems with the vertical offset with my screen height? I'm not really getting the calculations I have to do to figure that out from the manuals (again...no projector selected yet).

A rough drawing that might help.
Thanks
Scott


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## gsmollin (Apr 25, 2006)

The pj should be mounted about 18 inches below the ceiling. This prevents hot air from getting sucked into the inlet. If this is a basement theater, then I think you can relax that rule since the ceilings are less hot than upstairs, but a flush mount may still give trouble. With a hush box and forced ventilation, that problem gets transferred to the hushbox design. The vertical offset looks OK, but always check the adjustment range of your model, and stay away from the extremes of the range.


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## alan monro (May 9, 2006)

gs. The correct height of the projector should be roughly at the top of the screen . The horizontal offset seems a bit extreme , it all really depends on the projector whether it has a decent horizontal Keystone Effect compensator . As far as I know not many projectors have horizontal adjustment . Also good projectors will not spill light . Kind regards , Alan.


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## gsmollin (Apr 25, 2006)

Yes, about the top of the screen, and at least 18 inches below the ceiling, unless it is below grade. Then it can be maybe half that, but a flush mount against the ceiling will commonly have heat problems because the exhaust air will spread out across the ceiling. The hot exhaust air can't rise anymore. The picture is an elevation view. We don't know what the horizontal offset is.


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## Guest (Jun 21, 2007)

Mine is almost exactly like that configuration. There won't be a problem by the time the projector is hanging from a bracket. The only problem of any kind is that the proj as a noise source is only about 1.5 m from the centre seat. It's ok most of the time but in very quiet moments one notices it.


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## Anthony (Oct 5, 2006)

If you must be offset, make sure your projector has a lens shift feature. I have a Sanyo PLV-Z4 and it is atop the equipment rack in the back/right of my room. No ceiling mounting, just sitting on its feet. It's approximately even with the screen top and about 40" offset to the right. Distance is roughly 18' onto a 92" screen.

I went with the PLV-Z4 because it had this kind of mounting flexibility.

A friend of mine has a Panasonic 9000 (if I remember that right), and it has a horizontal shift and can be closer to the screen than mine.

I'm not up on current state of the art, but I imagine these features are available in the newer crop of 1080p projectors as well.

Be sure to check out ProjectorCentral.com They have some good calculators and a lot of reference material on which projectors work where.


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## Fincave (Apr 20, 2006)

I have the Sanyo Z3 and the lens shift allows for one full screen shift up or down and for half the screen's width shift to either side though it is not possible to use both the shifts to their full limits. My pj is mounted almost directly overhead and to be honest the movie has to be pretty boring for me to notice any noise from the pj (running the pj in eco mode). As mentioned previously, projector central is a good place to look in regard to placement and throw distances etc.


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## tbase1 (Nov 10, 2006)

The Z4 is a solid performer for the price ,and it has a long throw to boot. This is good if you what to go with a anamorphic lens.


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## <^..^>Smokey Joe (Jun 29, 2007)

Why not build an adjustable mount?

Like mine.










In place.










The shaft allows the projector to slide up to the ceiling, where I have a pin to lock it in place. 
(note the walls are going to be the shade that is on the test spot to the right, the yellow really effects the calibration)


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## mechman (Feb 8, 2007)

Nice mount smokey! Wish I would have seen that a year or so ago!

mech


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## gsmollin (Apr 25, 2006)

<^..^>Smokey Joe said:


> Why not build an adjustable mount?
> 
> Like mine.


Ans: I don't have the machine tools to make this mount. Besides, I don't see any pitch or roll adjustment.


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## wbassett (Feb 8, 2007)

<^..^>Smokey Joe said:


> Why not build an adjustable mount?
> 
> (note the walls are going to be the shade that is on the test spot to the right, the yellow really effects the calibration)


Excellent mount Smokey!

About those yellow walls... hmm, I seem to always see someone using yellow or mustard color walls and never really liked that idea for what you just said.


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## <^..^>Smokey Joe (Jun 29, 2007)

Lens shift, no need for pitch and roll. 

Although with this sort of mount one has to be critical with leveling whilst setting up. I've revisted level adjustment several times.

Actually I want to build a slightly longer tube(lower by 100~200mm) and move it back 0.5~1m to improve on distortions caused by the Lens.


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## MatrixDweller (Jul 24, 2007)

If you mount it in front of the i-beam you could make a shelf or box connected to the i-beam. After you frame around the i-beam so that you can attach drywall you might be down a good foot. You could get a quiet 12v PC fan and connect it to the 12v trigger on the projector if needed. As long as the intake is unobstructed and has a supply of cool air and the outtake is not polluting the intake you should be fine. Be careful if the AC vent is blowing close to the PJ if you have heat in the winter.

10'6" is a pretty good throw distance and should be good for most projectors on a 92" screen. It might almost max the zoom out on some though.


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