Joshua Provost said:Joe,
The motion picture standard is a 180 degree shutter angle. So, half the frame rate. 24p = 1/48 shutter. 30p, 60i = 1/60 shutter.
If you want to do a 50% slow mo, cut the shutter time in half: 1/96 or 1/120.
Josh
Excellent-- thank you for the clarification!