• Red and Blue data generate the most “noise.” Since both the red and blue photosites aren’t repeated in the Bayer pattern, there are fewer of those color data points from which to predict each pixel’s value. Worse still, when the light hitting a red or blue photosite is low, noise becomes a significant possibility in the photosite’s value (see “Noise,” below). For example, you’ll sometimes see noise in the red channel of a blue sky, or noise in the blue channel for a skin tone. Since the blue photosites are the least sensitive to light, indoor lighting can be a real problem for the sensor, as very little blue wavelength light is generally produced by incandescent lighting, and the lighting indoors tends to be dim to start with. Indeed, overall, the blue channel on the D200 tends to be the noisiest (at least until the camera’s noise reduction circuitry comes into play), and this problem is