I like to shoot on 300 fps
the idee is to do this with the RED (first time with the RED), but several things are not clear.
1. Can someone explain me how I can make a good choice in the relationship between Shutter speed <-> frame rate. to avoid motion blur, ore to create motion blur. I was looking of a kind of table. I like to understand this better.
2. And I heard that the RED goos from 5K to 2K (for slow motion) and crops the image from (example 16mm to 35mm) is that correct?
I'm not a RED user, but I'll address your framerate question...
Typically, unless there is an aesthetic, stylistic, or technical reason not to, you want to shoot at what most people consider a "normal" shutter speed. Normal being, back in the film world, a shutter speed that you'd get in a film camera with a 180° shutter.
The easy math for this is "One over twice the frame rate."
So, if you are shooting 24fps, a "normal" shutter is 1/48th of a second. At 30fps, it's 1/60th. And so on. For the 300fps footage you want to do, a normal shutter would be 1/600th of a second (pretty darn fast, certainly not for dim interiors).
Shooting within the "normal" range will give you the amount of motion blur (or lack of it) that is appropriate for your frame rate. If you're shooting pretty fast action at 24fps, you want the degree of motion blur that the 1/48th shutter speed gives you... your brain needs that blur to interpret the motion smoothly. Conversely, the short 1/600th shutter speed with your 300fps is going to give razor sharp images with virtually no motion blur... which is what would be appropriate since playback is going to have action that is sooo slow.
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