Projector & Screen Basics Page 3
Other useful features to look for include multiple lamp brightness modes and, if you plan to use an anamorphic lens setup, an anamorphic aspect ratio setting.
Most projectors use a conventional projection lamp, but a few new projectors employ LED lighting. These offer reduced energy consumption, almost unlimited LED life with no age-related dimming, and other advantages. The main limitation is the price (and sometimes brightness). Current models sell for $15,000 and up.
A larger screen (of the same gain) than those used in our reviews will have reduced measured brightness in roughly direct proportion to the increase in screen area. A projector that can generate 20 foot-lamberts on our reference 78-inch-wide screen should provide at least 12 ft-L on a screen up to about 100 inches wide. 12 ft-L is a comfortable brightness level for most viewers, even if some viewers demand more.
If the projector deviates from the standard color temperature and color gamut, the result won’t be an accurate reproduction of what the director intended. Even the best projectors often come out of the box with poorly calibrated color temperature. At a minimum, you’ll want both high and low controls for red, green, and blue to get this right. You should also be prepared to pay an experienced and fully equipped calibrator to do the job (it’s not a DIY operation for most of us). A properly implemented color management system (CMS) can also help you get the color points right, although it’s best if the gamut is correct on arrival. Unlike color temperature, color gamut sometimes is.
There are a number of ways to measure contrast, or more precisely, contrast ratio. But there’s some disagreement among experts as to which is more significant. The type we measure is peak contrast ratio, or full-on/full-off contrast ratio. This is the spread between the brightness of a peak-white window (100 IRE) and a full-screen black test pattern (0 IRE). The higher this number—assuming it’s measured with the projector set up for the best and most accurate picture quality it can produce—the better.
The full-on/full-off contrast ratio alone isn’t enough to characterize the effective contrast. You also need the black level. Without deep blacks, the image may look pale, two-dimensional, and washed out. At the current state of the art in projectors, a black level that’s much above 0.01 ft-L (under our measurement conditions) is mediocre at best. At or below 0.005 ft-L is good, and 0.002 ft-L or less is superb. You won’t get this number from any published specs; check out our reviews.
Gamma indicates the brightness of the image at all points along the full brightness range between pure black and peak white. Per- haps the most important aspect of gamma is how quickly a projector comes out of pure black as the image becomes brighter. If it does this too fast, it can undo the positive effects of even the darkest blacks. If it does this too slow, the blacks will look muddy and crushed. The only way you can find out if a projector’s bottom-end gamma is appropriate is through a well set-up demo or the comments in a good review.
Apart from the cheapest models, there’s little reason today to choose anything less than a 1080p projector. 720p models still exist, and they can produce a fine picture, but you shouldn’t pay a premium price for them.
Resolution is more than just pixel count. The entire optical path, from light source to lens, is involved. None of the projectors we’ve reviewed in the recent past suffer from poor resolution. They all produce sharp, crisp images, particularly on HD sources. Are some sharper than others? Yes, but the differences tend to be elusive.
Most projectors incorporate respectable deinterlacing and upscaling. We check video-processing quality in our reviews, but I can’t recall the last time a projector’s video processing has affected a recommendation.
Different projectors handle 1080p/24 sources (from Blu-ray) differently. You should look for one that displays such material as a direct multiple of 24 fps. Most do. A few projectors even offer frame interpolation features that provide smoother motion. Some viewers don’t like how this feature changes the look of film-based sources, but others consider the added smoothness a bonus and a fair trade-off.
Many in-store projector demos are notoriously poor. If you’ve never seen a good home projector, a competent demo should blow you away. More than likely, you’ll get the best demo at the home of a friend with a competent front projection setup. Failing that, a good review will almost always tell you more about a projector than you’ll see in any but the best-equipped independent retailers. Don’t necessarily be put off by a well-reviewed projector in a bad store demo; they’re far more common than good ones.
Wrapping It Up
It should be obvious that getting a good projection setup is a bit more complex than simply buying a flat panel and plunking it down on a convenient stand or mounting it on a vacant wall. But it isn’t that difficult if you approach it in an organized fashion. Choose the right room, select your screen size and type, and then find the best projector to match your setup and budget. Once you do, you’ll wonder how you ever did without it, and you’ll never look at home theater in quite the same way.