i USE A 35MM F2 ASPH SUMMICRON MOUNTED ON A M6TTL BOTH TWO YEARS OLD AND I CAN TELL YOU THAT THE THIS LENS IS SUPERB.

I shoot mainly monochrome and colour transparencies , when the trannys are projected they literally jump out of the screen and bite you with their sharpness and colour saturation.
the lens is not cheap but well worth the cost if you can save up for it like I did.