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Photoshop: Levels Adjustment (Tonal Range)

Version: Adobe Photoshop CC 2020. Be aware that different versions of Photoshop will vary in appearance and functionality. Full Guides: Photoshop: Images, Photoshop: Graphic Design


Adjustments in Photoshop are a group of editing tools that can be used to manipulate color and tone without permanently changing the image. Adjustment layers can be edited and discarded in order to restore the original image at any time. Common Adjustments include Levels, Brightness & Contrast, Vibrance, and Color Balance.

The Levels adjustment gives fine-tune control over tonal changes, including the ability to adjust color channels separately (red, green, and blue). In addition to Levels, the Brightness/Contrast Adjustment can be used to adjust tone (see Photoshop: Brightness/Contrast Adjustment for more details).



To change an image’s tonal range with the Levels Adjustment:
  1. Select the Levels adjustment in the Adjustments panel. A Levels layer will be added in the Layers panel, and a Properties panel will open.
    • If the Adjustments panel isn’t open, navigate to Window > Adjustments. 
  2. Change the settings in the Properties panel. Under Channel drop-down, make sure RGB is selected. To adjust tones for a specific color channel, choose a color in the drop-down (red, green, blue).
  3. Click-and-drag the shadow, midtone, and highlight sliders to change their values. Move the black and white sliders to meet the end of the histogram to re-distribute the pixels evenly, shown below. Changes made will automatically apply to the image. 

Histograms

Proper usage of Levels requires an understanding of histograms. A histogram illustrates how pixels in an image are distributed by graphing the number of pixels at each color intensity level. The far left side of a histogram shows the shadows (black), the middle shows the midtones, and the far right is highlights (white).

Histograms that are skewed to the right are over-exposed (too bright), graphs skewed to the left are under-exposed (too dark), and graphs more evenly distributed are properly exposed. In most cases, the optimal distribution is to have values ranging all the way across. 

Empty parts of the graph means that no pixels of that color exist in the image. For example: an empty left side in an over-exposed image means no black pixels are present, because everything in the image is too bright. This can be fixed with the Levels adjustment.



In the image below, the black and white sliders are moved to meet the ends of the histogram to re-distribute the pixels evenly.



Modifying Adjustments

After adding an Adjustment to an image, a new layer is created for the adjustment in the Layers panel.

showing where to edit adjustment layers
  • To re-open adjustments later, double-click on the adjustment’s icon in its layer. The adjustment’s Properties Panel, with any changes made, will appear.
  • To delete an adjustment layer, click-and-drag the layer to the trashcan within the Layers Panel.


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Keywords:editing, images, photos, adjustments, tone, levels, brightness, exposure   Doc ID:91924
Owner:Misty B.Group:Pacific Lutheran University
Created:2019-05-22 15:43 PDTUpdated:2020-09-25 13:34 PDT
Sites:Pacific Lutheran University
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