My simple idea for 2.35:1 adjustment...any suggestions?

Why not paint a 2.35:1 screen and then place your projector such that the zoom out will fill the 2.35:1 screen and the zoom in will do your normal 16:9 (1.78:1) with the Velcro idea on the sides.

nj. i have implemented this idea before on my first (blackout cloth) screen. i just used strips of felt to mask and rolled it up when i didn't need them. i didn't use any type of backing to keep it rigid. the problem i had with this is that the fabric (felt, velvet(ine), etc) is flexible and stretchable. eventually, i started pulling it way too much and i wasn't getting that nice straight edge where the black bars were. i made a design in which i would use some type of rigid backing for the masking, so there wouldn't be any business of stretching or anything. it would've been lightweight enough that velcro would've worked. however, my new screen is a gray screen and i decided that the blacks were black enough that i didn't need any masking at all.

bud. i'm trying to imagine the solution you posted. if he just had a 2.35 screen and just zoomed in to fit a 16:9 image, wouldn't the image be smaller? it probably wouldn't be a big deal if the intended screen size is large enough anyway though. anyhow, maybe his projector will be ceiling mounted and would be a hassle to go up to zoom the lens every time? digital zoom perhaps? not sure.

If your projector is ceiling mounted and real high and no auto zoom, Yes this wouldn't very well. If you have a normal basement theater as many do with say a drop ceiling at 7 or 7.5 feet and the projector is dropped a little it's not so hard to reach the zoom adjustment. The idea behind doing it this way is you still get as big of a 16:9 screen as you would the other way but you will have a constant height when you go to scope movies and even bigger. This is really only going to work if you can get the projector in exactly the right place, (throw length) and two have a wide enough room for the extra width in scope movies 2.35:1. the idea is that most people don't watch a lot of 2.35:1 movies and on that special showing you make the adjustment and view the whole screen. The rest of the time you have side masking that swings in like shutters from the side.

As for the issue of masking I have been a proponent of no masking from day one here. Like afx I think with my gray screen and DLP blacks I'm happy without masking all the time. I switch AR's a few times every evening and I would go nuts switching it all the time. What I found and liked was the flat black wall behind the screen and the screen floating away from the wall. I know that look isn't for everyone but I like the no trim look to the screen with the projector on and off.

Below thumbnail will give a idea of how the gray DIY masks.
Area below the 16:9 image is the gray screen it shows pretty accurately in this photo and can be compared to the black walls to the right and left. I do have to find a flatter black for the ceiling, and the white milk boxes are going to go as soon as the two 12 subs get done. I might not be to fussy but once the movie starts I forget about all that stuff.

A solution that costs more money and is not simple is to scale all ouput to a constant ratio. Probably can't do this with HD material, but with SD DVDs and an HTPC you will have no problems to convert