High-gain screens are typically designed for use in classrooms or multimedia environments. Their narrow viewing angle makes them a poor choice for most home theaters. Some glass-bead screens (also known as retro-reflective) are especially good at reflecting light directly back in the direction of the projector. These are best used when you have a projector mounted on a table and want to show the image in a small viewing area, such as a conference room. Although high-gain screens definitely have their place, they tend to suffer from hot-spotting, where the image is reflected unevenly across the screen as viewed from a single seating position, causing some areas to be brighter, or "hotter." Many high-gain screens also suffer from color shifting, meaning that they treat red, green, and blue differently, so they're usually not what you want to be using in a critical viewing environment such as a dedicated home theater.
Aspect Ratios
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The Next Step in Screen Technology
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| Projection-screen technology for the home has come a long way from the basic pop-up screen in the 8mm days to the fantastic realms of dedicated rooms and 1.78:1-format widescreen images. Some even say we're on the verge of another big leap in home theater with the introduction of products such as Stewart Filmscreen's 2.35:1 CineCurve screens, which are indeed curved. These super-wide screens have been around for a while, but they've only recently been gaining serious consideration for the typical dedicated media room — thanks to the popularity of Runco's CineWide system, which uses anamorphic lenses to create 2.35:1 images that completely fill the screen. At the moment, achieving this requires a considerable investment in projectors, lenses, scalers, screens, and control systems. But as with all technology, the prices will continue to fall. |
Thanks to the advent of widescreen TV, the average person has become aware of the term "aspect ratio." Although many people still might be a little confused by measurements such as 4:3, 2.35:1, and 1.78:1 (which describe the screen proportions, with the first number representing the width and the second the height), they're having better luck grasping the difference between widescreen and full-screen TVs. Projection screens are available in several formats, including standard TV (4:3, or 1.33:1) and widescreen HDTV (16:9, or 1.78:1) as well as CinemaScope (2.35:1 or 2.4:1). Most home theater projectors use 16:9 HDTV as their native format, and most installations today use 16:9 screens.
I usually design mid-level home theater installations so the owner has the option of upgrading the screen to 2.35:1. HDTV is still the main focus in these home theaters, and most clients are willing to live with the black bars above and below the image during any 2.35:1 movies they might watch. In higher-end installations, anamorphic lenses can be used with a standard 16:9 projector to display an image on a 2.35:1 screen. (See "The Next Step in Screen Technology".) Motorized masking closes in the sides for 16:9 viewing. Screens built for this kind of viewing are also known as "constant height" screens. At the moment, however, it requires a decent amount of money to make the experience of using one of these systems seamless.
