[Terry Lecroix]

The whole shutter angle thing goes back to film shooting. At 24 fps the exposure for one frame is 1/48th of a second with a 180 degree shutter.* The frame is exposed for 1/48th of a second and then the shutter blocks the light for another 1/48th of a second while the next frame of film is brought to the gate for the next exposure. If your intention is to emulate film motion artifacts then turn on the 180 degree shutter. Obviously the shorter exposure time with cut into your low light sensitivity a bit.

Terry LeCroix
TerryLeCroix.com