OTHER TECH

Q. I'm concerned about the accuracy of the standards used for professional HDTV calibration. In ISF-calibrated sets, the color white always has some other shade mixed in that makes it look slightly gray, brown, or green. But the whites I've seen on most uncalibrated HDTVs look more like the color white as it appears in reality. So, how valid are the ISF standards? JOHN LANG / CRANBERRY, PA

A. The main goal of ISF calibration is to adjust the TV so it can reproduce a grayscale (the range of individual brightness steps from black to white) that closely tracks a 6,500-K color temperature. As you've seen, white tones on ISF-calibrated sets don't always jibe with the popular conception of white; on a properly adjusted TV, the whites will have a slightly red, creamy look.

But this isn't some random thing. The 6,500-K color-temperature specification - or more precisely, the D65 standard illuminant as defined by the CIE, an international technical-standards-setting organization - is widely accepted as a standard representation of average daylight. The standard is followed by a wide range of industries, including motion-picture and TV production facilities, which routinely adjust the monitors used for film-to-video transfers to D65. When your TV gets calibrated, the ISF technician is attempting to get your set's picture to look the same as on those pro monitors. Even if the resulting picture doesn't match your subjective perception of reality, ISF calibration is still based on a valid and reliable standard.