What does a 3 bladed shutter do differently from a 2?

Nothing apart from project each frame 3 times, producing an image flicker frequency of 72hz.

A 2 bladed shutter produces 48hz.

If we chop off one of the blades in a 2 bladed shutter (not the pulldown mask obviously, unless we want this effect) we will get 24hz, representative of 24fps image acquisition rate.

To Come…..

next im going to measure the angles to see if its a 3:2 light/dark ratio.