What Randy just described seems to be one of the big attractions of the Prismasonic products. With a Panamorph lens, either vertical compression or the new horizontal expansion, you have to physically remove the lens, either with one of Panamorph's very high quality motorized transports (which cost about the same as the lens) or with a DIY-equivalent made from a couple of drawer slides and a scrap of plywood. Fortunately the alignment between lens and projector does not seem to affect image quality, although a real cheap DIY transport probably results in some image shift.
For anyone not completely sick of my own HT adventures, I have "plan B" up and running. Turns out that if you have the projector at the right height, you can get the right amount of vertical image shift "for free" when you zoom between the right settings for 2.35:1 and 16:9.
In my case I wanted the 2.35 image to be aligned at the top of the screen so that eye level would remain 1/3 of the way up from the bottom of the image. That meant the projector lens needed to be about an inch above the bottom of the 4x8 screen, or raised about 4" from its current location on the top of a picnic cooler (don't ask).
The results are great. I have to manually zoom when switching aspect ratios but no shifting required, ie other than keeping greasy fingers away from the lens the aspect ratio change can be handled by anyone. When visitors bring kids who might be watching unattended the plan is to leave the screen masks at 16:9 and live with a slightly smaller 2.35 image. This what the HT geeks call "constant width operation" and the rest of us call "stop mucking with the projector and watch the movie".
All I need now is to add some masks to the screen. I need about 7" of fixed masking above the top of the screen to handle the black bars which splash over the top when zoomed in for a 2.35 movie, a moveable 7" mask at the bottom of the screen, and 2 moveable 6" masks at the sides. I'm thinking about trying to rig a bit of a shadow box around the screen as well, which would also provide a "parking spot" and protection for the unused masks.
Here's a link to a guy who did a nice setup with fabric masks, only his system aligns the images at the bottom of the screen rather than the top. I think this was necessary because his screen is mounted higher than mine :
http://dustin.bunnyhug.net/One note I should make re: previous posts. Earlier I said that a constant-area rig was a good alternative to a "big honkin' 2.35 screen". After some thought I have refined this -- constant area is a good alternative to a "big 2.35 screen" or a "big honkin' 16:9 screen". Jakeman runs a really big 16:9 screen in his HT and the 2.35 movies look fantastic... but then his screen is almost 10 feet wide.
