Contrast Adjustment Layers:

Lets look at another technique we can use to improve the contrast in our document. Instead of using Adobe Photoshops Auto Contrast Feature, we can add an Adjustment layer where we can control our photographs brightness and contrast. It is possible to simply go to Image > Adjustments > Brightness and Contrast, however, by using an Adjustment layer, we can go back and alter our adjustments later, and use layer masks if wanted. To add a new Brightness & Contrast Adjustment Layer, go to Layer > New Adjustment Layer> Brightness/Contrast:

A dialogue will come up with some options. If you want to use your previous layer as a mask for your adjustment layer, check the box below your new layers name. This will make this adjustment only effect parts visible in the previous layer.

Click Ok, and another settings box will come up. In this one, you can customize your images contrast yourself rather than automatically. For my photograph, I am going to increase the contrast by 25, and decrease the brightness by -5.

You can see the improvements made using this adjustment in the example below.

These are the basics to improving your images contrast!

Section 3 "Levels explained"