86 Technical Issues: Killing the Gremlins
FIGURE 5.5 “Spring Field Background.” Pictures like this, with large areas of a single color, are more likely to show noise. © Douglas Freer/
Shutterstock
image has been underexposed. While this can be corrected later,
in the process of making adjustments to brighten the image using
curves or levels in Photoshop, you will increase visible noise in
the image, particularly in the darker shadow areas of the image,
especially if you are working in 8 bits. The histogram on the right,
Figure 5.7B, is much better, with lots of data from the shadows to
the highlights, but the highlights are not “burned out.” The only
difference between the two images used for these examples was
the exposure setting.
Of course, you might fi nd that your shot is overexposed, in which
case you’ll need to reduce the exposure, not increase it. Try if you can
to expose so that there are data all the way to the right but not beyond
it. Not all cameras allow you manually to set the exposure, and gener-
ally it is not necessary to do so. However, it is normally possible to