Detailed Course on Achieving the Tyndall Effect by PS Skills

I usually refer to these as "crepuscular rays", "god fingers" or "sun rays."

The Tyndall effect is similar to Rayleigh Scattering, applied to light scattered by wavelength-sized particles rather than sub-wavelength molecules, and has nothing to do with crepuscular rays.

(and why this is on Hacker News rather than Digital Photography School or similar site is anyone's guess)