Eye AF at f/1.2 — RF 85mm f/1.2L DS
At f/1.2, the depth of field on an 85mm lens is approximately 2.5 centimeters at typical portrait distance. That is the width of a human eye. Focus must land on the near eye, precisely, every frame. The reason to own an RF 85mm f/1.2L DS is the RF 85mm f/1.2L DS — and the reason it is usable wide open is Eye AF on the R5 Mark II or R6 Mark II.
This is not a historical camera review. It is an observation about how one technology redeems another. The 85mm f/1.2 focal length and aperture combination has always been technically viable; what made it impractical was the human inability to manually confirm focus on an eye, in ambient light, with a moving subject, repeatedly. Eye AF removes that constraint without removing the optical character that makes the lens worth owning.
The DS variant — Defocus Smoothing — adds a secondary optical element that modifies the bokeh rendering. The out-of-focus areas draw softer, without the double-line outlining that some faster lenses produce. Whether that matters to you is a taste judgment, not a technical one. What does matter technically is that the DS coating reduces transmission by approximately one stop, so the lens shoots at f/1.2 geometrically but transmits at roughly T1.4. In most ambient light conditions this is irrelevant.
The practical setup: subject tracking on, Eye AF set to prefer nearest eye, servo AF. The camera locks before you decide to fire. What remains is your decision about distance, background, and timing. The camera has removed the mechanical failure mode. The creative failure mode is entirely yours.
Shoot at 1/800s minimum at f/1.2 outdoors to prevent motion blur from compounding focus precision. Even a correctly focused eye will render poorly if the subject moved during the 1/400s exposure. Sharpness at this aperture is not just a focus problem — it is a shutter problem too.
The lens does not forgive. The camera compensates. Between them, you have enough room to work.