post-production editing
Step 1a - Levels and white point
The fi rst step is a critical step and needs to be performed with due care and attention before
rushing on to the creative enhancements. It’s classifi ed as a single step as the changes are all
being made to either the Background layer in the main editing space or the sliders found in the
camera RAW dialog box (see chapter ‘Camera RAW’).
The process begins with optimization of the histogram. In the Levels dialog box the black and
white sliders (directly beneath the histogram) are moved in to touch the information recorded
by the image sensor. This procedure sets the black and white points within the image. Holding
down the Alt or Option key as you drag these sliders will help you locate the darkest and brightest
pixels within the image. The overall brightness of the image can be adjusted by moving the central
gamma slider to the left or right without upsetting either the black or white point in the image (see
chapter ‘Exposure’ page 37).
Note > The Brightness/Contrast feature in the main editing space does not respect the black
and white points when making its adjustment and will more than likely lead to clipping if
used. The Brightness and Contrast sliders in the camera RAW dialog box do not share the
same destructive nature as their namesakes in the main editing space.
Correct the color or white balance of the image if required by moving the gamma slider in either
the Red, Green or Blue channels or by simply clicking the Set Gray Point eyedropper and then
clicking on a tone in the image that should not have any color, e.g. a black jacket, gray hair or white
shirt. This is usually quick and easy but can prove problematic if the tone you are clicking on has
a refl ective surface or is being illuminated with very cool or warm lighting, e.g. late afternoon sun.
When the dynamic range, brightness and white balance has been adjusted click OK to apply the
changes. You can apply these changes directly to the background layer if you are working in 16
Bits/Channel or by using an adjustment layer if working on an 8 Bits/Channel image.