HD100U and Mini35 grain on footage
 

I am test shooting with my HD100U and the Mini35 with Nikon lenses. However, I seem to get a bit grain. Is that because of lowlight, the Nikon lenses, the Mini35? perhaps the GAIN affected some test shots.

Anyone with suggestions to how to keep a clear image but still get the "filmlook"?

I shoot be posting some footage soon, but the files are LARGE, like 150 MB.

Thanks