Brightness, Contrast, and Levels

The most basic image adjustment tools in Photoshop are all concerned with an image’s Luminance. Luminance is the quality and relationship between brightness and darkness.

There are many ways to do similar tasks in Photoshop. The following offer different ways of adjustment.

Auto Correction and Brightness/Contrast

Like any automated processes, these features are easy to use, but often do not produce the best results.

Image→Adjustments→AutoLevels

Image→Adjustments→AutoContrast

Image→Adjustments→AutoColor

Correcting with Brightness/Contrast is a slightly more elegant way to improve an image, allowing brightness and contrast of an image to be manipulated independently. Better still is using two similar tools, Levels and Curves.

Image→Adjustments→Brightness/Contrast

Correcting with Levels

The better way to adjust an image are using Levels or Curves (next). This method allows for you to ‘calibrate’ the image by assigning whitepoint, midpoint, and blackpoint areas, and Output Levels

Image→Adjustments→Levels

Correcting with Curves

Curves are the best way to adjust brightness and contrast of an image because with Curves you can adjust highlights, midtones, and shadows, as well as any other area of an image Image→Adjustments→Curves

Read: What is the difference between Levels and Curves?

Channels

Both Levels and Curves in Photoshop allow you to edit the individual Color Channels of an image. Photoshop creates RGB images with three ‘channels of light’ – *R*ed, *G*reen, and *B*lue. When these three channels are viewed together, they create the intended image.

These channels can be adjusted independently within the Curves and Levels Adjustments and can be viewed separately in the Channels Window, Window→Channels

Correcting with Shadows/Highlights

This tool can aid in correcting big differences between over and under-exposed areas of a photograph.

Image→Adjustments→Shadows/Highlights

The Effects of Image Tone

Changing the tone of an image has significant effects on the ‘tone’ of the message the image sends.

Read: OJ’s Last Run: Time Covers It From All Angles