Color correcting digital camera images Page 2 of 2

Cast out bad color with Photoshop’s Curves tool

Tip: First steps

Before you correct even a single photo, go to the Photoshop toolbox and click on the Eyedropper tool (or press the I key). If you look up in the Options Bar, you’ll see that the tool’s default Sample Size setting is Point Sample. The problem with this setting is that it gives you a reading from just one individual pixel, rather than giving you an average of the area where you’re clicking (which is much more accurate for color-correction purposes). To fix this, change the Sample Size pop-up menu to 3 By 3 Average. When you’re working on very high-resolution images in Photoshop CS3, you can choose larger sampling areas, such as 5 by 5, 31 by 31, and even 101 by 101.

Finding a neutral gray

Finding a neutral midtone while color correcting has always been kind of tricky. That is, it was until Dave Cross, who works with me as the senior developer of education for the National Association of Photoshop Professionals, came into my office one day to show me his amazing trick for finding exactly where the midtones live in just about any image.

Step One Open a color photo, and click on the New Layer icon at the bottom of the Layers panel to create a new blank layer. Select Edit: Fill. Choose 50% Gray from the Use pop-up menu in the Contents section.

Step Two Go to the Layers panel and change the blend mode of this layer to Difference. This doesn’t do much for the look of your photo, but don’t worry—the change is only temporary.

Neutral Midtone: A Threshold adjustment layer helped us locate the neutral midtones in this photo.

Step Three Choose Threshold from the Create New Adjustment Layer pop-up menu at the bottom of the Layers panel. When the dialog box appears, drag the slider all the way to the left (your photo will turn completely white). Now slowly drag the slider back to the right, and the first areas that appear in black are the neutral midtones. To help you remember exactly where one of the areas is, hold down the shift key, move your cursor over that spot, and click once to add a Color Sampler tool point just as a reminder. Then click on the Cancel button in the Threshold dialog box.

Step Four Now that your midtone point is marked, go back to the Layers panel and drag the gray layer onto the Trash icon to delete it. You’ll see your full-color photo again. Now press Command-M to open Curves, get the midtones Eyedropper, and click directly on that Color Sampler point.

[Scott Kelby is the editor in chief of Photoshop User magazine and the president of the National Association of Photoshop Professionals.]