Here's an attachment for high-end projectors from SIM2 that will keep you from wasting pixels when you're displaying those ultra-wide letterboxed images. The Cinema Flex system uses a combination of lens and projector settings that let you see that whole 2.35:1 aspect ratio, using those pixels where they can do some good rather than wasting their time projecting those black bands at the top and bottom of the screen. Now you can use every pixel your projector is capable of displaying.
How does it work?
It does that by first electronically stretching the picture vertically, covering those pesky black bands at the top and bottom. So far, the image is distorted, so it takes it a step further and stretches out the image using an anamorphic lens. That way, it's the perfect 2.35:1 aspect ratio. Neat trick, but it's not cheap.
The SIM2 Cinema Flex is $3195, and $5995 for the motorized version, and it only works with SIM2 D80, Grand Cinema HT3000, and C3X projectors, starting at around $6000.
Plus, it's making that image wider and less tall for those glorious 2.35:1 images, and that might be the wrong shape for your screen. If that bothers you, you can get screens that automagically expand and contract with the aspect ratio. So this is a high-end endeavor, no matter how you slice it. But there's nothing quite like seeing a movie projected in a darkened room, perfectly replicating that cinema experience.
Product Page [Sim2, via Sci Fi Tech]