Does your 24mm pancake lens back focus?

drmikeinpdx

Celebrating 20 years of naughty photography!
I'm notoriously picky about autofocus accuracy. All my lenses have been AFMA'd with the bodies that allow that. But the 77D that I use for travel photography doesn't offer AFMA.

I bought a 24mm pancake when they first came out and really liked it. I even did a little macro photography with it on the 77D that turned out well a couple of years ago.

A few months ago, I tried some mild macro photography with the 24 Pancake on the 77D and found that it had enough back focus to make it useless for macro work. Shortly after that I bought a 90D and a new copy of the 24 pancake lens, thinking that the old lens might have been damaged internally. (There was no external damage and I don't think I ever dropped it.)

Oddly enough, the new 24 pancake back focused the same amount as the old one. I mounted it on my new 90D and discovered that it needed -3 on the microfocus adjustment scale. But I really want to use it on the 77D which has no adjustment! It focuses well with other lenses - just retested with the 40 pancake and the nifty fifty, it hits the mark perfectly.

So I'm asking if any of you have checked the focus on your 24 pancakes? What did you find?
 

Maximilian

The dark side - I've been there
Nov 7, 2013
2,698
523
Germany
Does the BF only appear near MFD or at other distances as well?
Does it only appear at wide apertures or also from f/5.6 on.
I haven't done much MFD pictures so I would need to check that out.

Only one I could find ad hoc is that one, shot near MFD and at f/2.8 with my old 100D, but that body seeemd to have a general AF problem.
Focus was on the middle of the bloom, so if I look at the water drops there might be some BF as well.

tired_dandelion_f2_8.JPG