MinutePhysics Explains Star Shapes

Most lens flares, especially artificial ones in VFX, have a star-shaped thingy around bright light sources. And every comp software has its own tool for this, whether it’s called glint, glare, highlight and so forth. This video explains the physics behind these star shapes and the correct chromatic aberration if you fake them (spoilers: red is diffracted the most).

With the knowledge from this video, you can make your own star-shaped diffraction patterns using a fourier transformation. Nuke has a tool for this.