The 85 was on my D750 and the 90 was on my Pentax 645nii. Since the 90mm was made for Pentax 67 system, it needs an adapter for it to work on their 645 mount. Both audible and LED focus confirmation work through the adapter. As far as the focal length is concern, 67 90mm on a 645 is about the equiv lance of 60-65mm of about f1.4 on 35mm cameras. I also have their 67 105mm f2.4 (about the equivalence of 75mm f1.2) but I feel the 90mm suits my style a bit better and more versatile. All Pentax 67 lenses are manual focus. I generally color correct the skin tone from my digital to match with film (close but can't get it exact), and add contrast to my film scans.