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Discussion Starter · #1 ·
I have a small TV-room. Wall to wall it's 10.5 feet. Do you guys think I can still use a DLP/LCD projector?


If I put the screen directly on the wall, and put a projector on the opposite wall, I imagine the throw distance would be something like 8.5-9 feet (does this seem correct?), and viewing distance something like 7.5-8 feet. Is this doable? What would be the largest picture size I could get, theoretically and practically? I imagine something like 55" would be OK.


I would only use the projector for DVD's, not TV (not HDTV either). I've seen the Sony VPL-CX1 SuperLite for about $1800, that's the one I'm thinking of. Is that a decent projector for this?


The reason I'm thinking of FP is that it would hopefully give me an extra 2-2.5 feet of viewing distance, so I could get a larger picture, compared to an RPTV.


Any ideas or thoughts about this?


/Mike
 

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Hi Mike,


When you say the room is 10.5 feet wall to wall do you mean from side to side or front to back (with back where the projector will be and front where the screen will be)?


I also have a small HT room, originally it was 10.75 feet wide and 15.5 feet front to back. The width is about the minimum to accomodate a couch. The 15.5 feet depth dictated that I could only use a 7' wide screen (assuming a G11U w/ standard lens). The results have been outstanding tho. I eventually moved the wall with the screen back another 3 feet so that I could accomodate two tiers of couches and I'm very happy with the results.


There is a calculator on one of the projector websites that will give you an idea of the throw distance of the various projectors and the maximum size that you will be able to use. Perhaps one of the other members can dig it up as I don't remember where I saw it.


Cheers!


Mark


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Behold the Power of Cheese!!
 

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Here is the link I mentioned:
http://www.projectorcentral.com/projection_calc.cfm


In addition to throw distance and image size there are other considerations to think about such as overal brightness of the image and the screen gain to use. Another thing to think about is that the closer you sit to the screen the more noticeable screen door will be. My first tier of seating is about 10' away from the screen which works out to be about perfect (for my tastes) with a DILA. With a projector with more pronounced screendoor however (such as an LCD) you would want to sit farther away.




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I just recently got a vpl-cx1, and for the money I consider it to be a great starter projector. I was trying it at about 14 feet with a 80-85" diagonal screen, and sitting about 12 feet back and I didn't notice much screen door. Since then I moved the projector back to 20' so I could get the image up to about 125-130" and have noticed more screen door. At 55" I think you should probably get a pretty decent picture, and I don't think you'll see much screen door even at 8'. Maybe I'll try moving mine up tonight to see what happens.


P.S. I took a look at the CX1 manual, it says for a 60" image to put the projector between 8-10' away from the screen, so at 55", 9' away you should be alright.
 

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Hi Cain,


I'm using a Stewart Grayhawk. It's 7' wide with a 16x9 aspect ratio. If I had known that I would be moving a wall 3 feet, I would have gone with an 8' wide screen instead. All in all tho, I'm very happy with it.


-Mark



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Mike,


You might want to investigate the ISCO II anamorphic lens. If it will work for your projector it should give you a large image with high resolution - less screndoor with anamorphic DVDs. Problem is the ISCO II is pricey, but offers a possible solution for small rooms!


Cheers,


Grant
 

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Grant is correct. If you take a projector, and lets say the throw ratio is 1.5x the screen width. At 8' away, you would have roughly a 5.5' wide screen...regardless of the aspect ratio. However, if you added an ISCO II lens, the image would be optically streched in the horizontal plane by 33%, giving you more like a 7' wide screen. Not to mention that it would allow you to use the full resolution of the projector and make the pixels smaller. So in a nutshell...you definitely have options.


Thanks!


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Jason Turk

AV Science, Inc.
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716-454-1460 ext.204

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You can also look for projectors with shorter lenses.


The (in)famous NEC LT150 has a throw ratio of only 1.33, meaning that you get a larger picture at a given distance than, say, with a 1.5 lens.


The Infocus 340/350 would also be ones to look at.
http://www.projectorcentral.com


has an extensive database on projectors. You can generally compute the throw ratio from the data there. Note that zoom lenses will have two throw ratios, corresponding to the minimum and maximum focal lengths.

 

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Discussion Starter · #10 ·
Thanks for all the replies!


Mark, I mean front to back. The room is 10.5 by 13, but the seating will have to be on the long wall, not the short wall, unfortunately.


Jon, thanks for your input about this projector. Seems like a good buy for $1800 to me. Like I said, HD is not going to be shown on this projector. It is my understanding that this projector will not accept a 480p signal.

How is the internal line doubler?


So, the general consensus then is that it could be done?


And, with a small image (as far as projectors go at least) like the one I had in mind, would the screen door effect really be noticable, especially since this is an XGA projector? How much is that ISCOII lense (I am on a very tight budget http://www.avsforum.com/ubb/smile.gif )


Or do you guys think I'd be better off investing in a (similarly priced) 40"-47" RPTV, like the new ones from Toshiba, Sony and Panasonic? The problem, like I mentioned, is that the viewing distance would be cut short with about 2 feet, due to the depth of these RPTV's. Would I get a better picture on the Sony projector (around 55"-60" picture) from 8 feet away, or on an RPTV from 6 feet away (picture size around 40"-47")?


By the way, this is not really urgent, it will be a while before I can do anything, but it's always good to have a plan... and to speculate! http://www.avsforum.com/ubb/smile.gif


/Mike

 

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I agree with Chris in that I think you'll be happier putting the screen on the short wall. Small rooms like ours always involve compromises. Either seating is restricted (screen on short wall) or PQ and viewer fatigue is compromised (screen on long wall).


When faced with the same dilemma I built some simple legs for my screen and experimented with placement. At least in my situation it became evident that the screen had to go on the short wall.


Bottom line tho, it's your HT Room and only you can decide what works best for your situation http://www.avsforum.com/ubb/smile.gif


Cheers!


-Mark



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Discussion Starter · #12 ·
I will investigate my options further. I am very happy to see that you guys have done similar things though, I thought all hope was lost... http://www.avsforum.com/ubb/smile.gif


BTW, my room looks like this:
http://www.geocities.com/fawlty70/tvroom.html

(sorry about the javascript errors, they're generated by GeoCities pagebuilder, don't know how to get rid of them)


Oh, and there's a window on the short (bottom) wall.


That's why it can only go on the long side. At least I can't think of a way to get an advantage by doing it some other way.


It's fun to plan though. http://www.avsforum.com/ubb/smile.gif


/Mike


[This message has been edited by Micke S (edited 08-09-2001).]
 

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Depending on what's on the other side of the wall, you might consider cutting a hole in the wall and projecting through it. This not only gives you additional throw length, but by placing glass over the opening you eliminate heating and minimize fan noise problems.


If your walls are standard 16" studs, you can use up to about a 14" wide hole, and that means you're getting an additional 19-21" of throw length, or about an extra foot of screen width. The height of the hole needs to be 3/4 or 9/16 or 27/64 of the width, depending on image aspect ratio.


Or take out part of one stud and get about 2 extra feet of screen width. Or...


Obviously, this wouldn't work for a CRT projector.


-yogaman
 

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I have my theater in a small room about your size. I put the screen in what was a closet, giving me 2 extra feet. You can also put the projector in a closet to get it farther back from the screen. I think you'll be a lot happier with screen on the short wall. I can't imagine any situation where you could not achieve this, especially with a retractable screen.


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Christopher Young

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I wouldn't go rptv as I personally think you need to be sat quite far back from these to avoid picture brightness irregularities (dimming off axis etc ).My HT is in a room approx 10ft by 8ft with a picture about 5'6" wide. I bought my Philips projector partly for it's short throw (It was also cheap ). Be wary of fan noise, in a small room it is really noticable. The Sony HT lcd's 10 HT & 11 HT have short throws and quiet fans, also the forthcoming Plus Piano is, according to early reports, very quiet and has a short throw distance.
 

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I'm a newbie with a similar situation. The best spot for the projector is the middle of the couch. I'm using a Da-Lite HighPower screen, which limits the viewing angle, so I don't want to use a ceiling mount. I could raise the couch on a platform, and put the projector under it.


Are there any problems with using a mirror to fold the light path (either 90 or ~180 degrees)? I know I should use a front surface mirror to minimize light loss and prevent a double (ghost) image. Something like the Da-Lite 27448 (18 inch x 30 inch front surface mirror, 94% reflectivity) is around $150 and would let me move the projector 20-30 inches closer.


I've done experiments with a small regular mirror. Folding the path back almost 180 degrees reverses left/right, which is fixed by setting the "Rear Projection" option. It was hard to tell if there would be any affect on keystoning.


Any mirror experiences to share?


Dan

 
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