CHAPTER 9 HOW SOFTWARE CHANGES PIXELS BY THE NUMBERS^151
Overexposed images can be more difficult to correct
than underexposed photos. Overexposed images
can lose details in the highlights, yielding white
areas with little or no information.1
Here, the boats run together
without borders. The more
sensitive human eye can dis-
tinguish among different
shades and intensities of
paint used on the boats.
Those subtleties are lost when
the camera captures so much
light that the distinctions are
washed out.2
Correcting the image can’t add the needed detail.
Although the digital corrections to exposure make the
blue sail darker along with the brown gear on the near
boat, it can’t pull out details that weren’t captured
because of the overexposure.3
Only the correctly
exposed photo
contains enough
detail to distinguish
between the white
boats. This is why,
even when you’re
taking digital pic-
tures, it’s better to
lean toward under-
exposure than
overexposure.4
Overexposure
Overexposure, when too much light gets into the camera, can be corrected
much in the same way, by recalibrating the lightest and darkest pixels, and
then by darkening pixels in the mid-toned colors and highlights.