Projectors with lens shift:
Since all the other projectors have adjustable lens shift, your only restriction to screen size is if it fits on your wall, with the minimum height off the floor that you find acceptable (without the top of the projector hitting the ceiling).
For example, with that 128 inch screen and a projector with lens shift, the screen height (excluding frame), is about 63 inches. Thus, even with an 8 foot ceiling height, you could have the screen surface bottom as high up as 33 inches (96 inch room height - 63 inches of screen height = 33 inches). Now that would have the top of the screen flush with the ceiling, and doesn't allow for the screen's frame, so if you have a four inch frame at top and bottom, the 33 inches becomes 29 inches.
Please remember, we calculate the lower number from the bottom of the screen surface, not from its frame, so the bottom of the frame would be at 25 inches (29 - 4) with a four inch wide frame.
Anamorphic Lens Support
Using an anamorphic lens lets you use a 2.35:1 aspect ratio screen, the same ratio as most movies (which we will refer to as Cinemascope movies) use. The combination of screen and lens means no letterboxing at the top and bottom when watching most movies.
By "anamorphic lens supprt" we mean that the projector has the built in (internal) stretch scaling to properly resize the image to work with an anamorphic lens. Any projector can work with an anamorphic lens, even without this, but it would require an outboard processor to handle the correct scaling. Consider those outboard processors to start at around $800, with products like the recently reviewed DVDO Edge.
All of the projectors in this report have internal support for an anamorphic lens, except the following:
Optoma HD20, BenQ W1000, Vivitek H1080FD, Epson Home Cinema 8100*, Home Cinema 8500UB*, Pro Cinema 9100, Sony VPL-HW15
Also of note, is that some projectors with recessed lenses do make it difficult to mount an anamorphic lens and sled in front of them. Still all of them do have a solution, at least from one manufacturer. The Sanyos and JVCs are examples of projectors, where your choices of anamorphic lens providers is at least a little limited.
* While these three Epson projectors do not have the internal support, the almost identical Pro Cinema 9500UB does support one. So if you want an Epson, and plan an anamorphic lens, and Cinemascope shaped screen, choose the Pro Cinema 9500UB. That will cost less than pairing one of the other Epson's with an $800+ outboard processor that can adjust of an anamorphic lens.
Emulating an Anamorphic Lens Setup
Panasonic is the only company to provide an anamorphic lens emulation solution. Simply stated, they allow you to change the zoom position (it is motorized) when working with a 2.35:1 screen. In the wider zoom position, a Cinemascope movie just fills the screen. When you need to watch 16:9 or 4:3, you zoom out, so that those sizes do not overshoot the top and bottom of the screen.
What makes it work, is that Panasonic lets you save the lens positions, so that it is easy to toggle back and forth - as easy as controlling a real anamorphic lens/sled.
It's not a perfect solution, but it's free, and that compares well to the typical $4000+ for a lens/sled combination from a major manufacturer. The limits - the reasons it isn't quite as good, are two fold. First, when filling the screen with Cinemascope content, the letterboxes are still there, but they exist above the top of your screen and below the bottom. If your walls are light colored, you will still see them, but if your walls are dark (or you have dark draping around the screen), the letterboxes will be invisible.
The second downside relates to brightness. Panasonic's emulation still produces those letterboxes, so you are only using about 80% of the pixels for the movie image. With a real setup, you use 100%. Thus, you get about a 25% brighter image with a real lens/sled combo.
Lastly, The Panasonic has a 2:1 zoom lens ratio - that's about as good as it gets. However to support the two lens positions, you give up about half of your placement flexibility, reducing the working range. You won't be able to place the projector as far back. As a result, in many rooms you will no longer be able to rear shelf mount.
By the way, any projector with at least a 1.5:1 zoom lens can do the same thing, but since projectors are typically mounted where its inconvenient to reach them, it's not practical for projectors without motorized zoom and focus. (Who wants to climb a ladder every time you want to switch from a movie to HDTV or back?) If the projector has enough range, and motorized zoom and focus, such as the Sanyo PLV-Z700 and PLV-Z3000, the JVC RS10 and RS20 to name a few, you can do the same thing as the Panasonic does.
The difference is you will be using your remote to make the zoom changes, and it will take a minute to get the size just right, and possibly refocus. By comparison, the Panasonic does it at the touch of a button, setting the zoom and refocusing. Nice touch! Keep in mind that adjusting the zoom repeatedly on any projector is likely to throw the focus off, at least a little. That's why Panasonic's Lens Memory, uses it's auto focus technology to refocus after each time you change the zoom setting with Lens Memory.