- CR Quick Recommendations
- Ratings
- Recommendations and notes
- Features
- Important features
- Complete features glossary
- How to choose
- Is a projector for you?
- HDTV Types
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Important features Front-projectors
Maximum image size. Manufacturer specs indicate the largest image you can get from a given model.
To achieve the maximum size, you have to move the projector farther back from the screen. But as the image gets larger, it also gets dimmer. In our tests, we found an image size of about 110 inches (measured diagonally, for a 16:9 widescreen display) to be the sweet spot for impact and brightness.
Distance to screen. To fill a 110-inch screen, you'd typically place a projector 10 to 15 feet away. For a 50-inch image, about half that distance would do. Recommended placement varies by model; see what the specs indicate.
Keystoning. If you tilt the projector up or down to raise or lower the projected image, the sides of the image will start to angle away from 90 degrees. That turns what should be a rectangular shape into a trapezoid. A keystoning control feature compensates for this, but resolution can suffer depending on the amount of correction applied to the image.
Lens-shift mechanism. This feature lets you move the image horizontally or vertically without tilting the projector, so you can get a straight, geometrically correct picture even if the projector can't be centered directly in front of the screen without the shortcomings of the keystone adjustments. The electronic shift adjustment on some projectors tends to have a very limited range. When exceeded, images could be cropped.
Dynamic/manual iris. A manual or dynamic iris acts as a brightness adjustment by varying (typically reducing) the amount of light sent to the lens, effectively boosting contrast. While a manual iris lets you reduce overall light output to improve black-level performance, it applies that light reduction across the entire picture, so whites won't be quite as white. A dynamic iris, which is controlled by a motor, has circuitry that automatically closes the iris during darker scenes and opens it up again for brighter scenes. It must be able to react accurately and quickly or the process will be noticeable, an effect known as "breathing."
Stretch and zoom modes. These aspect-ratio controls will adjust the image size to fill the screen shape better. This helps reduce or eliminate the dark bands that can appear above, below, or on the sides of the image. (The picture may be distorted or cut off a bit in the process of stretching and zooming.)
Inputs. Most projectors have at least one HDMI and one component-video input to handle HD signals. Most also have S-video and composite-video inputs, and many have a computer input.
Maximum image size. Manufacturer specs indicate the largest image you can get from a given model.
To achieve the maximum size, you have to move the projector farther back from the screen. But as the image gets larger, it also gets dimmer. In our tests, we found an image size of about 110 inches (measured diagonally, for a 16:9 widescreen display) to be the sweet spot for impact and brightness.
Distance to screen. To fill a 110-inch screen, you'd typically place a projector 10 to 15 feet away. For a 50-inch image, about half that distance would do. Recommended placement varies by model; see what the specs indicate.
Keystoning. If you tilt the projector up or down to raise or lower the projected image, the sides of the image will start to angle away from 90 degrees. That turns what should be a rectangular shape into a trapezoid. A keystoning control feature compensates for this, but resolution can suffer depending on the amount of correction applied to the image.
Lens-shift mechanism. This feature lets you move the image horizontally or vertically without tilting the projector, so you can get a straight, geometrically correct picture even if the projector can't be centered directly in front of the screen without the shortcomings of the keystone adjustments. The electronic shift adjustment on some projectors tends to have a very limited range. When exceeded, images could be cropped.
Dynamic/manual iris. A manual or dynamic iris acts as a brightness adjustment by varying (typically reducing) the amount of light sent to the lens, effectively boosting contrast. While a manual iris lets you reduce overall light output to improve black-level performance, it applies that light reduction across the entire picture, so whites won't be quite as white. A dynamic iris, which is controlled by a motor, has circuitry that automatically closes the iris during darker scenes and opens it up again for brighter scenes. It must be able to react accurately and quickly or the process will be noticeable, an effect known as "breathing."
Stretch and zoom modes. These aspect-ratio controls will adjust the image size to fill the screen shape better. This helps reduce or eliminate the dark bands that can appear above, below, or on the sides of the image. (The picture may be distorted or cut off a bit in the process of stretching and zooming.)
Inputs. Most projectors have at least one HDMI and one component-video input to handle HD signals. Most also have S-video and composite-video inputs, and many have a computer input.
