The following is an excerpt from Michael Freeman's "Digital Image Editing and Special Effects" (Focal Press, $24.95).
There could be any number of reasons why you may feel it necessary to adjust the colors in an image. It might be that you simply want to boost the overall color of an image for a more saturated look; alternatively you may want to single out one particular color to increase or decrease saturation without affecting the rest of the colors in the image. Whatever color adjustment you want to make, you’ll get the best results using the Hue/Saturation command. This is a powerful tool that lets you make color changes quickly and easily.
When you choose your camera's user settings, it's advisable to set the color saturation control to a minimum, unless you're intending to print directly from the camera. Although this will usually result in images that lack color right out of the camera, it does mean that you can color correct the image in a much more controlled manner using image-editing software, rather than relying on your camera's processor to get it right for you.
Once the camera has embedded the color settings, it’s often difficult to change them should you want to—especially if you’re shooting JPEGs—without degrading the image. Here a Hue/Saturation command was used and the Saturation slider moved to the right to boost the overall color. A fairly strong setting was used to make the most of the warm reds of the sunset.
1: This photograph of fishing boats has attractive, nicely saturated colors, but the yellow nets in the foreground are not as vivid as they seemed at the time of shooting.
2: If we increase the overall saturation of the image so that the nets are brighter, the result is distinctly oversaturated colors across the board. Not the result we want.
3: One of the benefits of the Hue/Saturation command is that you can select specific colors to enhance using the pull-down menu. By selecting “Yellows” we can increase the saturation of the yellow hues in the image without oversaturating the rest of the image.
4: If you’re working with raw files, Lightroom offers a powerful color control panel that features three sliders—Hue, Saturation, and Luminence—for each of the key eight colors—Red, Orange, Yellow, Green, Aqua, Blue, Purple, and Magenta. The sliders let you target specific color adjustments with accuracy.
Although the Hue/Saturation dialog is a powerful and relatively versatile tool, when it comes to making really specific color corrections it’s necessary to use the command in combination with other tools. In this example, we need to select and correct a very specific color without affecting any of the other colors in the photograph. This is a good example of a very localized correction that simply would not be possible to accomplish using a raw conversion program.
This striking image of a humming-bird hawkmoth in flight has captured the insect well. However, the Valerian on which it is feeding appears too red (perhaps reflected light from a red colored wall). The Hue/Saturation command on its own will not be able to isolate the color of the plant as it is a mixture of a number of subtle hues.
Instead, we select the Eyedropper tool from the Toolbox and click on a particularly red part of the plant. Having sampled the color, we’ll next go to Select > Color Range. This brings up the Color Range dialog box. This shows all the elements of the picture that share the sampled color in white. Moving the Fuzziness slider to the right will widen the selection. Here we’ve set the slider so that most of the plant has been selected.
Having set the Fuzziness slider, clicking OK will make the selection, outlined by the familiar marching ants.
Now that we’ve isolated the offending color, we can use the Hue/Saturation command to change the color of the selected area. Hiding the marching ants selection by pressing Ctrl/_ + H provides us with a clear view of the plant as we’re making the adjustment.
Experimenting with various Hue settings, and reducing the saturation a little, provides us with a much more accurate color— important to keep the botanists happy! Using the Color Range command is an excellent way of selecting an area of an image for corrections other than just color.
Dodging & burning
Dodging and burning are old darkroom terms and involve making specific areas of an image either lighter (dodging) or darker (burning). In the days of black-and-white printing, the dodging and burning process was considered a fundamental creative process in order to arrive at the final printed result. Conventionally, dodging was carried out by masking certain areas of the print so they would receive less light as the photo was being exposed, thereby making them lighter.
Other areas that received additional light during exposure became darker when the print was developed—and these areas were said to be “burned” or “burned in.” Using the digital Dodge and Burn tools has the same effect, but they are much easier to control, and you can always go back a step if you don’t like the result.
This photograph of ferns was shot in dappled sunlight, with light scattered by the canopy of the tree’s leaves. The fern shows up quite brightly against the relatively dark bark of the tree behind, but we can use the Dodge and Burn tools to emphasize the effect.
With the Burn tool selected, a fairly strong exposure was set in the Tool Options bar, and the Range kept to the default Midtones. Next, with an appropriately sized brush, the Burn tool was painted over the trunk of the tree to darken it.
Once all the areas that needed darkening were burned in, the Burn tool was replaced by the Dodge tool. Similar values were set in the Tool Options bar, and another brush size selected, which covered just the ferns.
It’s better to Dodge and Burn gradually, making several passes over the relevant areas. That way you remain in control of the adjustment. The finished result picks out the fern, making it stand out against the backdrop.
TIP You’ll find you’ll get much better results using the Dodge and Burn tools with images in 16-bit mode. So don’t convert any images you’ve opened as raw files into JPEGs (or reduce them to 8-bit) if you’re intending to use these tools. Alternatively use the Adjustment brush in Lightroom or Aperture and adjust the exposure to lighten or darken selected parts of the image.
Michael Freeman is a veteran professional editorial photographer. While he has written 66 books on the craft of photography, Freeman has also released a total of 135 books selling more than 4 million copies. Freeman is also the author of "The Black & White Photography Field Guide" and newly released "The Photographer's Eye: A Graphic Guide" and "The Photographer's Eye Course," a book and DVD package, all published by Focal Press.