Brightness and Contrast and Color Balance

Prior to initiating any retouching, you will want to perform an overall evaluation of the image and make any adjustments to its brightness, contrast, and color balance. Local retouching should be performed only after these primary image enhancements have been completed, because they will affect the nature of the local adjustments. Although these global correction skills are covered in detail in post “Tonal and Color Corrections,” we are including them here as part of the workflow required for preparing an image for local cloning, retouching, and ultimately printing. Plus, in this section we are including a few tips on performing color correction of faces in the absence of neutral tonal areas.

To get started, make a duplicate copy onscreen (Image --> Duplicate), leaving the original at a diminished dimension to refer back to. Our first concern is the overall brightness and contrast of the image, which is low. Our second area of interest is skin tone ratios. You will want to consider both of these issues simultaneously because the specific technique you use to adjust the brightness and contrast should be affected by whether you have a problem with the color cast in the skin tones.

As with most images, you should start with a Levels adjustment layer. Even if you don’t use it, it can be helpful in evaluating the distribution of data within the image and for determining the location of critical highlights and shadows. In addition to the Levels adjustment layer, we will place a couple of Color Sampler points to initially measure and then monitor Hope’s skin tone ratios. Here are some tips for performing this initial image evaluation quickly:

1. Type F7 to bring up the Info palette and place it near the image; you’ll refer to it in a later step.

2. Option/Alt+click the half-black/half-white symbol located at the bottom of the Layers palette and select Levels from the menu that appears. Name this adjustment layer B&C for brightness and contrast. Note: Using the Option/Alt key when you create anything new allows you to name it on the fly—a good habit to acquire.

3. When the B&C Levels dialog box appears, press your Shift key—this will automatically activate your Color Sampler tool—and click to place two Color Sampler points on Hope’s face. Place the Color Sampler points where the lighting is best/most direct (not great anywhere here) and at locations where there are no obvious blemishes. Remember that one of the big benefits of using adjustment layers is that you can perform and reperform as many edits as you like; all the edits are nondestructive until you flatten  the image. (Note that you should flatten only a copy of your final image, leaving your layered PSD file in a fully editable state.)

4. In the Info palette, note the RGB values: point 1 = (156,109,79), point 2 = (159,104,74). These are acceptable RGB skin tone values (see the following sidebar), and although you can fine-tune these ratios to suit any specific look you want, these values do  not require correction.

5. Now let’s focus attention on the histogram in the Levels dialog box. We can clearly see the main source of the low brightness and contrast; nearly all of the image data in the histogram is positioned to the left of the center (midtone) slider, which places the median tonal value of the image somewhere below the three-quarter tone.

6. The quick adjustment, which would have a big impact on the overall brightness and contrast of this image, would be to reposition the slider on the right (the Master RGB channel highlight slider) to the left, until it lines up under the histogram directly where  the beginning of the significant data in the image begins, the base of the bump in the histogram data peak. There are no print-critical highlights in this image, so making this qualitative adjustment is safe. Note: If the RGB ratios had not been acceptable, we would have made the highlight adjustments on individual channels instead of the Master RGB channel. In addition, we might have added a Curves adjustment layer as well to adjust the RGB ratios in the midtone areas, if necessary. This is why it is critical to evaluate both the brightness and contrast and the color balance in an image so that we would know whether we could use the Master RGB channel highlight adjustment (as we did here), or whether we needed to perform separate channel adjustments and maybe  add a Curves adjustment layer.

7. Time for some fine-tuning: In images such as this one, which has no critical highlight area to guide you (as evidenced by the blank area to the right of the histogram), I recommend dragging the highlight slider (the right slider under the histogram), until the lightest RGB values in the skin tone reach the mid 240s (about 5%). You can refer again to the Info palette to determine these values. Here the red values will be your guide. Note that a third Color Sampler point was placed on the lightest area of the skin to monitor the red value of this point (you can determine the lightest area of an image by Option/Alt+clicking the highlight slider as you pull it to the left with the Preview option enabled). It finished up at 242. By focusing on 242 as your target value, you are guaranteeing that these areas will print with detail in all the colors, because they will be at or higher than the 5% (242) minimum printable highlight value.

8. Using the Info palette, take one final look at the RGB values in the adjustment layer adjusted image. Note that the RGB value ratios still have R greater than G, which is in turn greater than B (R > G > B).