Basic Digital Darkroom Tools
To get the most from your photos, start with the basic photographic tools. These tried and true adjustments to the photographic image will improve your photos considerably and highlight areas of photography that you might want to learn more about.
You can find these tools and controls in the very popular Adobe family of photography products. The company offers a software package for just about every level of interest and experience, from the Photoshop Album Starter Edition for beginners to Photoshop Elements for casual photographers, all the way up to Photoshop Lightroom, Photoshop CS3, and Adobe Bridge for professional and commercial applications.
In technical terms, the brightness control is linear and the gamma control is nonlinear. The brightness control lightens or darkens everything in the image at the same time. The gamma control brightens or darkens parts of the image at different rates. Keep your eye on changes to the shadows and the highlights to get a feel for these controls.
If your exposure was not perfect, you may need to brighten or darken your image. This is generally the first step in correcting a photographic image. When you use the brightness control, it brightens the entire image step by step all at one time. A good rule of thumb is to brighten the picture until there is detail in the shadows but there is no loss of detail in the highlights.
For example, you may find that there is considerable detail in the shadows that lightening will reveal. However, once an area is overexposed, most detail is lost and darkening may not help. Do the best you can with the brightness control (or the gamma correction) until you have an image with a full range of tones.
This image was brightened to bring out more of the person walking.
The gamma control lightened the person walking without lightening the background as much as the brightness control.
In this digital darkroom adjustment, contrast was increased.
The gamma correction is quite similar to the brightness control but generally works better with digital images. When you increase the gamma number, the shadows are lightened faster than the highlights are lightened. This allows you to bring up the shadows while still keeping detail in the highlights. You should move the gamma number up or down (usually it is on a sliding scale) until the highlights start to become a bit pale or begin to seem a bit washed out. At this point you should back off a bit until the highlights are crisp and clear.
Gamma correction works especially well with flash images. It brings up detail in the shadows and makes skin look more natural, yet it does not wash out the highlights. If you want to get the best quality photographs, spend time looking at the subtle differences between gamma and brightness changes. You will often find that an image changes noticeably at a certain point, a tipping point, where the image starts to lose detail. When you find that point, back off a bit and the correction will be about right.
The ideal photograph has a full range of tones from white to black. It does not matter whether the photo is color or is monochrome. These areas of black and white are often subtle. Use the sliding contrast controls to find the precise spot where the picture has full contrast. Ideally you want a pure black in tiny areas of the shadows and a pure white in the highlights.
You will rarely use the brightness control or gamma correction by itself. After adjusting the image to bring out the fullest range of tones, tweak your image further using the contrast control. Aim for a photograph that catches your attention even when you are several feet away from your monitor.
These two photographic terms refer to darkening (burning) or lightening (dodging) sections of a photograph. In the film darkroom days, burning was often done with a hole cut into a piece of cardboard. A special wand-like tool with a circle of cardboard on the end was used for dodging. Accomplished photographers liked to use their hands. Now you can select tools to carefully and subtly lighten or darken your digital image.
This “bad” job of dodging to the person's face was done to make clear how selective areas can be lightened or darkened.