Absolute Beginner's Guide to Digital Photography

To correct an overly light image, do the opposite: Drag the black slider to the right

(not shown).

Correcting Brightness and Contrast for Low-Contrast Images

In the following image, there is practically no contrast (a common problem with

aerial photography because of smog and haze). The histogram shows no pixels at

either the black (left) end or white (right) end of the graph (see Figure 14.5). An

image with contrast too high would have peaks of pixels at the extreme black

and/or white ends of the graph.

CHAPTER 14 THE IMPORTANCE OF BRIGHTNESS/CONTRAST 209

FIGURE 14.5
The histogram
shows that this
image has no
contrast.

To increase contrast, drag the black-and-white sliders toward the middle of the graph

(see Figure 14.6). To create a very highly contrasted image, try moving these two

sliders very close together.

Note that this picture is still too dark overall. Move the gray slider triangle to correct

the image without changing the overall contrast. The gray slider transforms what-

ever pixel it is placed beneath into middle gray, a brightness value of 127, midway

between 0 (black) and 255 (white).