I just realized that I should test my nikon af 50 1.4, mf 50 1.2 AI-S, rokkor 58 1.2 and helios 44m 5 against each other. So first methology: tripod, liveview manual focus on all lenses, moving the tripod back to equate fov on the 58-lenses.
I tested them all wide open and at f/2.
First the helios at f/2: (only one shot from this one )
I am not impressed with the Nikkor f/1.2 at all but impressed with the slower f/1.4. The Rokkor seems to be the best of the bunch but really only by a smidgen.