Explore a comprehensive Photoshop tutorial that covers topics such as color correction with a Levels adjustment layer, setting white, black, and gray points, and advanced experimentation with Histogram sliders.
This exercise is excerpted from Noble Desktop’s past Photoshop training materials and is compatible with Photoshop updates through 2020. To learn current skills in Photoshop, check out our Photoshop Bootcamp and graphic design classes in NYC and live online.
Topics covered in this Photoshop tutorial:
Color correction with a Levels adjustment layer, Setting white, black, & gray points
Exercise Preview
Exercise Overview
Levels offers more fine-tuned control than Brightness/Contrast and Color Balance. This exercise walks you through using Levels to fix a photo’s color and contrast.
Adjusting Levels with White, Black, & Gray Points
From the Photoshop Class folder, open Chef.jpg.
At the bottom of the Layers panel, click the Create new fill or adjustment layer button
and from the pop-up menu, choose Levels.Levels will open in the Properties panel on the right. You’ll see a Histogram, or graph, showing the distribution of shadows (left), midtones (middle) and highlights (right) in the image.
Click the Set White Point button
to the left of the histogram.-
In the image, click on an area that should be white. Try to use the lightest area of the chef’s clothing.
The image will lighten. If it’s lightened far too much, simply click elsewhere in the image to set a different white point instead.
Click the Set Black Point button
to the left of the histogram.-
In the image, click on an area that should be black. Use the darkest area you can find—perhaps the chef’s hair or eyes, or maybe a shadow in the bowl of peppers.
The image will darken. If it’s darkened far too much, simply click elsewhere in the image to set a different black point instead.
Click the Set Gray Point button
to the left of the histogram.-
In the image, click on an area that ought to be a perfectly neutral gray. Try the chef’s clothing or the backdrop behind her. Experiment by clicking on different areas until you’re happy with the results.
NOTE: While most images have a true white and a true black, they do NOT always have a true neutral gray. So the Set Gray Point tool isn’t used as often as the Set White/Black Point tools.
Advanced Experimentation with Histogram Sliders
You’ve just practiced a quick technique for using levels. If you are going for precise adjustments, though, you may want to use the sliders below the Histogram.
-
Find the White Point slider
just below the Histogram. Slide it to the left.You’ll find that the image becomes lighter as more and more of the light areas become pure white.
Move the slider back to the right and the image darkens again.
-
Find the Black Point slider
just below the Histogram. Slide it to the right.You’ll find that the image becomes darker as more and more of the dark areas become pure black.
Move the slider back to the left and the image lightens again.
-
Find the Gray Point (gamma) slider
just below the Histogram.Slide it to the right—the image becomes overall darker.
Slide it to the left—the image becomes overall lighter.
To adjust the color balance, go to the top of the Levels dialog box and change the channel from RGB to Red.
-
Move the sliders to the right to darken the image by removing red. Move them to the left to lighten the image by adding red.
Experiment further if you like; but remember that the black, white, and gray point eyedroppers are an easy way to use Levels to improve contrast and fix color casts.