Nikon D7000 manual Overexposed

102 David Busch’s Nikon D7000 Guide to Digital SLR Photography

thinks is a middle gray, calculates an exposure based on that, and the feline in the cen- ter of the strip is rendered at its proper tonal value. Best of all, because the resulting exposure is correct, the black cat at left and white cat at right are rendered properly as well.

When you’re shooting pictures with your D7000, and the meter happens to base its exposure on a subject that averages that “ideal” middle gray, then you’ll end up with similar (accurate) results. The camera’s exposure algorithms are concocted to ensure this kind of result as often as possible, barring any unusual subjects (that is, those that are backlit, or have uneven illumination). The D7000 has three different metering modes (described next), plus Scene modes, each of which is equipped to handle certain types of unusual subjects, as I’ll outline.

Figure 4.4

When exposure is calculated based on the middle-gray cat in the center, the black and white cats are rendered accu- rately, too.

Overexposed

The strip of three images in Figure 4.5 show what would happen if the exposure were calculated based on metering the leftmost, black cat. The light meter sees less light reflecting from the black cat than it would see from a gray middle-tone subject, and so figures, “Aha! I need to add exposure to brighten this subject up to a middle gray!” That lightens the black cat, so it now appears to be gray.

But now the cat in the middle that was originally middle gray is overexposed and becomes light gray. And the white cat at right is now seriously overexposed, and loses detail in the highlights, which have become a featureless white.

Figure 4.5

When exposure is calculated based on the black cat at the left, the black cat looks gray, the gray cat appears to be a light gray, and the white cat is seriously over- exposed.