im looking into putting a pj into a small basement dedicated room 12'x18'. it currently houses four seats, surround setup and pioneer 151. front seats are about 7 feet from screen and back seats are about 13 feet back.

i suppose 90" screen is biggest i can go given front seats are 7 feet away. what do you guys think?

real issue is regarding pj placement. i assume i'll need to have the pj about 10-12 feet back to get a 90" image. doea the pj have to be directly centered to the screen? i may need to move the pj a few inches to the right to avoid a lower part of the ceiling. i want to keep the screen centered obviously. i assume this is possible but would like input from anyone. thanks.

There's a projector throw calculator online somewhere. For my build, I looked at the Mitsubishi one. Or see the PDF manual for any of the newer projectors. They have all that info in the "setup" portion of the manual. Have fun!

my room is about 11 x 19...

I have a 92 inch screen. My projector is about 13 feet back and my front row of seats is about 10. The rear seats are about 15ish. It seams to work good. The back row isn't ideal for sound but that is hardly ever used.

thanks for the replies. im still wondering if having the pj off-centre from middle of the screen can be corrected. does the pj have to be centred with the screen?

far better to center the projector and optimize it's location vertically so that no keystone adjustments need to be made, from my limited research.

Some projectors (panasonic) have a built in lens shift that allow the projector to be placed off center and the image is shifted over, with little need for keystone correction... they have both vertical and horizontal lens shifting... that combined with high zoom ratios makes the placement of these projectors extremely easy.

distance from screen to projector calculate.:)

Projector central (http://www.projectorcentral.com/projection-calculator.cfm)

Doug's Home Theater (http://www.avsforum.com/avs-vb/showthread.php?t=999923)

thanks for the replies. my issue with placement as i mentioned is a lower part of the otherwise very high 10' ceilings in my basement. the lower part comes down about 1' and protrudes out from the back corner of the wall. i would have to mount the pj about 8-10" from the lower protrusion.

im wondering what you guys think about the projected image and how wide the projected image would be about 2' in front of the projector. to put it another way: if you held your hand 1' in front of the projector how far to the left or right of the lens would you have to move your hand to not block the projected image? any ideas?

for your question it really depends on the distance from the screen, size of the screen and the zoom used (further away has a narrow image throw). The best way to figure that out is to get a projector in the basment... you don't estimates when it comes to that stuff.

Not to harp on lens shift... but you could offset the projector about half a screen and shift the image over to fit on the screen, that would completely solve your problem.

Not to harp on lens shift... but you could offset the projector about half a screen and shift the image over to fit on the screen, that would completely solve your problem.

would this be a concern wrt picture quality? thanks for the advice.