EF Lenses on R Mount (f/1.2 portrait primes)

CESA wrote:

Marco Nero wrote:

People using very bright lenses with very shallow DOF will sometimes find their shots are out of focus slightly, even on a Mirrorless camera. In almost all cases, this is user error and it happens for the following reasons:
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* Using the "Focus & Recompose Method" is disastrous with f/1.2 lenses.
* Keep the delay between AF lock and taking the picture to a minimum.
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If you attempt to 'focus & recompose' a shot, even with something static and up close, you will throw out the focus almost every time when using f/1.2 lenses. You just can't use that technique with these lenses because the moment you shift the direction of the camera, you are shifting the plane that the sensor is attached to. Mere millimeters are enough to ruin a shot completely.
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If you are a slow-poke who locks focus and then pauses before taking the shot, your body is going to shift slightly. All it takes is a couple of millimeters or more at f/1.2 and you've already lost the focus. Be more assertive and snap the shot the moment you hear that camera beep to confirm AF-lock.

Sometimes it's easier to focus a lens by moving the camera than to focus the lens. That "your body moves forward and back" can work for you at incredibly shallow depth of field, if you have good enough optics/optical viewfinder/rear LCD etc. to actually tell when something is in focus.

But getting the gears turning to move all that glass - that tiny moment where it goes from not moving to moving may be too big a jolt to make the tiny adjustment necessary to focus well (depending on how smooth the focusing ring is, if it's focus by wire etc.).

This actually works better at close distances than far - really close up it's easy to tell if someone's eye are in focus. Not so easy from a few feet away.