Sun Feb 18, 2018 11:22 pm
It depends on what you are shooting, but the actual “native” ISO for the 4.6K sensor in the Ursa Mini/Pro is actually 800 for optional results and IQ. If shooting in Raw, ISO is just meta data, and you can change the exposure in post on Resolve. If shooting ProRes, changing the ISO only changes the mid level exposure value on a curve (exposure curve) relative to high and low exposure values.
Unlike many video cameras, changing ISO on BM cameras does not add or reduce analog Gain, which is actually fixed. While you are correct on cameras that add additional analog Gain as you crank up the ISO, keeping the ISO down improves the image quality. But since BM cameras have a fixed ISO/Gain level, changing ISO only changes the exposure curve, and does not add Gain.
So I would recommend doing some test shots, under the lighting conditions you normally use, to see which ISO level works best for your workflow. Start at 800, then shoot the same scene at 400 and again at 200.
Shooting at 1600 does increase the video noise levels somewhat.
Cheers
Denny Smith
SHA Productions