The primary reason that cinematographers adjust the shutter angle is to control the amount of
motion blur that is recorded on each successive frame of film. A tight shutter angle will constrict motion blur. A wide shutter angle will allow it. A 180° shutter angle is considered normal.
So for instance, at 24
fps the "frame Interval" value is 0.04167 second ( = 1 / 24 ). Using an "exposure time" of 1/50 second gives a "shutter angle" value of 173°, very close to 180° (normal motion blur effect).
Tight shutters create a stuttering
stop-motion animation look that has become popular in action and war films. In particular, tight shutters are used to capture particles flying through the air, such as dirt from an exploding
mortar.