Image Processing Reference
The Shadows slider controls the black point in your image. The Shadows control is
equivalent to the black point, or left slider in the Levels command. The Shadows slider
has a range of 0 to 100, but typically you'll use values of 25 or less. The default setting
for Shadows is 5 when Auto is unchecked. As with Exposure, the best way to monitor
your adjustments with the Shadows slider is to use the Alt/Option key while making
adjustments (Figure 2.25). The colored pixels show which color channel is clipping.
White pixels indicate all color channels are being clipped and will result in pure black.
The Brightness slider works to set the overall brightness of your image by moving the
distribution of the pixels to the left or right without affecting the shadow or highlights.
Like the Exposure and Shadows sliders, the Brightness slider also has an equivalent in
the Levels command. Brightness works in the same manner as the center slider. To
brighten the overall tone of an image, move the slider to the right. The slider has a
range of 0 to 150 and defaults to 50 when Auto is unchecked.
Figure 2.25 By holding down the Alt/Option key while adjusting the Shadows slider, you can easily see
when detail is beginning to clip, or go out of range.
When using the Brightness slider, you'll need to keep an eye on the histogram to
see where the color values are going to ensure that you don't begin clipping colors.
The Contrast slider can add depth to your image and really make it come to life by
adjusting the midtones. With a range of -50 to 100, the default setting is 25 when Auto
is unchecked. Settings higher than 25 will add more contrast by darkening the values
below the midtone and lightening those above the midtone. Reducing the setting below