Color Correction and Enhancement with Adobe Photoshop CS4
Learning how to spot problems and then choosing the right correction technique is an essential part of mastering Photoshop. Several different tools are available, some more useful than others. By analyzing the most important tools and determining in which situations they might help you, a more thorough understanding of color correction is possible.
The primary purpose of Photoshop is to act as a digital darkroom, where images can be corrected, enhanced, and refined. How do you know an image needs touch-up? You can pretty much assume that every image can look a little (or even a lot) better than how the camera captured it. Whether it's adjusting the exposure, increasing contrast, or boosting saturation, Photoshop is the place to improve an image.
For example, in Figure 1, the image on the top is unretouched. The image on the bottom has been refined with three adjustment layers: one to enhance levels and two to adjust hue and saturation of the sky and vegetation.
Approaching Color Correction
New users often have a hard time when color-correcting or enhancing images. They generally lose sight of the goal: making the image look better and believable. Many users go "too far" in their quest to fix images. If the image starts to look fake or too altered, it will be distracting. While getting it "right" will require some practice, here's some general advice to get you started:
- Identify what's wrong. Before you can fix a picture, be sure you have decided on what's wrong. Is it too dark? Is the sky washed out? Has the picture faded over time? Make a list and prioritize the issues you find in each image. It's easiest to fix one problem at a time, and if you identify those problems, you'll know when to stop twiddling with the image.
- Work with a copy of the image. Before you start to color-correct an image, you should duplicate it. This way you can return to an original version if you make a mistake or go too far in your image touch-up. After opening your file, choose File > Save As and name the duplicate version that will be corrected. Color correction can be a destructive process, meaning that you cannot revert to the original state at a later time. By preserving an original version of the image or employing adjustment layers, nondestructive editing is possible. Some users also choose to duplicate the background layer at the bottom of the layer stack.
- Edit with adjustment layers. Adjustment layers allow you to apply most of the image-correction commands as nondestructive effects. They're added as a layer above the actual image; the adjustment layer can be blended, masked, or deleted at any time. Additionally, if you double-click the adjustment layer's thumbnail, you can modify its properties in the Adjustments panel (see Figure 2). The same modifications are available in both the Adjustments menu and Adjustments panel. You should work with an adjustment layer whenever possible because its flexibility will be important for future revisions.
- Get a fresh opinion. It's not a bad idea to step back and examine your work. Open the backup copy of the original image and compare it to the image on which you've been working. This before-and-after comparison can be very useful. If you have a fresh set of eyes nearby, ask that person for his or her opinion.
Photoshop offers several image adjustments, but only a few are used most often. Commands such as Levels and Curves are used by professionals to achieve outstanding results. You may need to take a little time to get comfortable with the professional imaging techniques discussed in the following sections, but the power they offer is worth your investment.