I will be using one of the following lenses on the black magic cinema camera. Since the crop factor of the sensor is 2.3 it will behave like a ' normal ' POV lens. I will also need the ability to shoot with a shallow depth of field so will be shooting wide open more often than not. For this reason can anyone say which lens is sharper when shooting with a wide open aperture? I already ruled out the Zeiss 21mm because it is slower, F2.8 while the other lenses are F2, and I do not think it would provide enough of a shallow depth of field.