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Hack #71. Reduce Lens Flare on RPTVs

Lens flare can dramatically decrease the black levels on an RPTV. Learn what lens flare is, and how to knock it out of the equation on your RPTV.

Although one expects CRT-based rear projection televisions to deliver good black levels, there is a factor that compromises black level performance in these displays. This factor is something called lens flare. Lens flare is most commonly seen in photographs. It usually occurs when the photographer is shooting in the general direction of the sun. Bright sunlight enters the lens at an angle and bounces around inside the lens body. As it reflects off of the interior parts of the lens, some of it ends up getting on the film, usually in the form of bright circles or shapes, smears of light, or lines.

Binocular, telescope, and camera lens manufacturers all try to make the inside of their optical assemblies as dark as possible, and also add light baffles to try to waylay the misdirected light so that it doesn't spoil the image.

Rear projection televisions also suffer from lens flare. Usually the best place to see lens flare is usually on the end titles of a film. Often the titles are bright white on a black background. Look for a small single title and pause the player at that point. Look at the black areas of the screen around the title. Is there a halo, ring, or general smear of light of the same color as the title? That unwanted light most likely is due to lens flare.

If you want to see the flare at its ...