Currently I have an Infocus 7205 projector with a 120inch screen. The screen is tight up against the ceiling which is painted white, and the image looks very washed out in bright scenes. This is not a dedicated home theatre so the white ceiling must stay, but I wondered if I could mount a rollerblind (with dark material) on the ceiling, and pull the blind towards the screen and then attach it to a hook.

I'm explaining this horribly, but if anyone understands what I'm trying to say, does it sound feasible?

I think I get what you are saying. I think a length of velvet might be your best bet. Just would need to figure out a way to tack it to the ceiling.

if you have a white screen, might also want to consider a gray screen. it should help quite a bit.

The problem with a blind in the horizontal position is that it will sag something terrible.

For skylights which need blinds, there are blinds made with tracks on the sides to keep them from sagging. They work very well, but for you installation, I doubt if you want the tracks fastened to the ceiling from an appearance standpoint. They are also a little pricey.

Assuming this doesn't have to be rolled and unrolled, I'd follow the suggestion above and put velvet cloth on the ceiling. Just staple it in place and fill any little holes when you dismantle the theater.

Anther approach might be to make a 1x2 from from a light wood, such as Aspen, and staple the fabric to it. That should be easy to fasten to the ceiling in some manner, and be completely removable.

Thanks Deane, forgot about the sag :(

My parents ould kill me if I done anything permanent to the ceiling, so I'll have to think of something else.

I like what Deane suggested, a frame of 1 x 2" & staple a black fabric around it. Then add legs long enough to snug the frame against the ceiling. Maybe you could paint the legs flat black or even build small columns to support the frame. But Deane is right, fabric sag might be a problem over time, may have to restrech it from time to time. Wonder if you could add cross braces with double sided tape to help hold the fabric in place.
Just a few ramblings...

Good luck with your project

John :D

I like what Deane suggested, a frame of 1 x 2" & staple a black fabric around it. Then add legs long enough to snug the frame against the ceiling. Maybe you could paint the legs flat black or even build small columns to support the frame. But Deane is right, fabric sag might be a problem over time, may have to restrech it from time to time. Wonder if you could add cross braces with double sided tape to help hold the fabric in place.
Just a few ramblings...

Good luck with your project

John :D

Exactly, I was just going to say build a nice looking black fabric velvet panel that will cover the ceiling area affecting the picture quality. Just rip some 2x4's into 1"x2" and build a square/rectangle where you can staple the fabric to the otherside.

EDIT: Also, may I recommend painting your ceiling in flat black to improve overall perceived contrast....that's if it's a dedicated theater room.

I'm in a similar boat; White ceiling but dont want to paint black.
Think I'm going to build a 4x8 panel from plywood, perhaps reinforcing ribs on the back, glue carpet cushioning foam to it on the "down" side. Then cover that with a black velvet cloth or black carpet and staple it to the back ( top ).
With 4 eyelet screws hang it from the ceiling at an angle. Holes are easy to fill when removed. This panel will serve to absorb both light and sound. When I clap my hands in my current bat cave-to-be there is an echo as well.
Going to do a similar wall treatment.

Simple. Get a motorized awning with your choice of velvet material.