In this tutorial we will learn how to create a realistic lightning with a very simple method using difference clouds and levels.

Step 1 Create Lightning

a) Create a new document
b) Open de Gradient editor and create a black and white gradient with a narrow gray area

c) Paint the document with a linear gradient

d) Apply difference Clouds: Filter > Render > Difference Clouds

e) Apply levels: Image > Adjustments > Levels
Set the levels as follows:

f) Inverse the image: Image > Adjustments > Invert

Step 2 Add Color

a) Create a new layer and paint it with a blue gradient

b) Set the blending mode to overlay

c) Select a soft, big round brush and paint some lights with a red or a violet color