FD 85mm 1.8 Vs EF 85mm 1.8 USM - Sony A7r

With well over 30 years between these two 85mm 1.8's it was interesting to see the minimal difference's over that time. Apart from the obvious inclusion of auto-focus to the canon range there isn't to much noticeable difference, both lenses display similar chromatic aberrations when extremely high contrast areas are heavily exposed and in focus. Although the FD shows slightly higher.

FD 85mm 1.8 @ F/1.8

EF 85mm @F/1.8

With the FD 85mm 1.8 being an all manual focus lens it does stake extra time to really nail the focus, Even considering the EF 85mm 1.8 mounted to the A7r is extremely slow AF, it's still faster then manual focusing in most occasions. Given the short focus throw of the FD 85mm 1.8 in my opinion it makes this lens better to MF, spinning the focus ring and moving your hand to spin the focus ring a second time isn't something I look for in a MF lens. Given it's a fairly fast lens of 1.8, the difference between in-focus and out of focus is very punchy, so using a standard MF technique of spinning back and forth watching the image pop until you feel it's in focus works very well. Focusing on someones eyes for a portrait shoot you would lean towards focus magnification to make sure the eyes and eyebrows are correctly sharp. Considering newer camera's have facial recognition AF the EF 85mm 1.8 is a lot easier for portraits - not having to move your MF point around the viewfinder to magnify each time a position changes.

The EF 85mm 1.8 is sharper wide open, with slightly higher contrast compared to the older FD 85mm 1.8, as you would expect from 30+ years of Design changes, R&D and manufacturing improvements. Once both lenses are stopped down to F2.8, the playing field really evens out considerably.

FD 85mm @F/1.8

EF 85mm @ F/1.8

FD 85mm @ F/1.8

EF 85mm @ F/1.8

These next comparisons show the difference in contrast and image sharpness wide open in the centre, As we would expect modern coating technology with advanced lens design has yielded better results in the same circumstances, although increasing shutter speed on the FD 85mm 1.8 would eliminate some exposure issues side by side.

At F/2.8 the FD 85mm 1.8 actually looks better in some area's, while both lenses overall improve greatly.

As the side by side comparison is centre crops of an incredibly detailed image with extremely small writing, real world results would rarely be noticeable to most people.