How Software Changes
Exposure After the Shot
150 PART 3 HOW THE DIGITAL DARKROOM WORKS
1
Colors will be made brighter to different degrees, depending on how dark they are, how
much of that color exists in the picture, and where they are located. If there are no absolute
whites in the photo, the lightest color might be brightened to white to increase contrast.3
In this example, as seen in the histogram,
underexposure was corrected by moving
the median light values toward the dark
end of the dynamic range.4
There are two different exposure problems that can occur when you
take a picture: underexposure and overexposure. These can happen
even with the finest digital equipment because not all subjects are
lighted equally nor are all photographers equally gifted in capturing
a scene. If the equipment doesn’t make a mistake, the photographer
will, sooner or later. Luckily both types of poor exposure can be
fixed in the digital darkroom.Underexposure
In an underexposed photo, too
many of the pixels have brightness
values at the low end of the
dynamic range. If you simply raise
the brightness of every pixel equally, you get a washed-out look. The digital
darkroom fixes underexposure by treating different levels of brightness
differently.Underexposure is a result of not enough^2
light getting into the camera. The shutter
speed is too fast or the aperture set too
small. Although you might not see them,
details of your image can hide in dark
tones and shadows.