Yes... it controls motion blur... that's what it does.
And for "normal motion blur" ...
all you do is DOUBLE SHUTTER SPEED of your video FPS
So if you shoot 30 frames per second shoot @ 1/60 sec shutter speed
and 24 fps shoot @ 1/48 (or 1/50)
to get the 180 degrees Shutter Angle (which produces that "normal motion blur"
https://en.wikipedia.org/wiki/Rotary_disc_shutter
~"So for instance, at 24 fps the "Frame Interval" value is 0.04167 sec. ( = 1 / 24 ). Using an "Exposure Time" of 1/50 sec. we get a "Shutter Angle" value of 173°, very close to 180° (normal motion blur effect)."
but shooting at faster than double: you get a more violent look that could be used for action scenes where you want it to look jerky and capture all the action.
^ AKA: The "Saving Private Ryan" Effect...
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Finally think I got it:
"MOTION TRACKING TEST: PFTrack, Maya, renderman RIS, & After Effects "
➨ https://www.youtube.com/watch?v=VVc9NX7i5RM
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