topic Re: EOS R - back-focusing slightly on AF in EOS DSLR & Mirrorless Cameras

EOS R - back-focusing slightly on AF

philobr — Sat, 31 May 2025 17:10:53 GMT

Hi there, I've noticed that my EOS R is back focusing slightly on AF, especially wide open.

When I set to one spot AF and focus on something where I think it should be sharp isnt, but its slightly behind.

If I switch to MF and use the guides its perfect, not a problem.

Any ideas on how to solve this?

Re: EOS R - back-focusing slightly on AF

Peter — Sat, 31 May 2025 22:55:52 GMT

With R5, R6, R7, R10 you can send the camera and lens to Canon to get an AF adjustment. Don't know if R also has that feature. Call Canon and ask.

Only with one lens model?

Re: EOS R - back-focusing slightly on AF

ebiggs1 — Sun, 01 Jun 2025 14:34:20 GMT

"If I switch to MF and use the guides its perfect, not a problem."

A lot of the time back focusing is caused by the user. It could just be how you focus and recompose or when using the camera's eye-detection autofocus and proper selection of the AF mode is important.

Re: EOS R - back-focusing slightly on AF

Waddizzle — Sun, 01 Jun 2025 16:09:07 GMT

“ A lot of the time (back/front) focusing is caused by the user. It could just be how you focus and recompose…..”

I agree with Ernie. If you are shooting handheld, then you can’t really draw any conclusions about the combo front or back focusing. Especially with a wide aperture lens. BTW, you made no mention of what lens(es) are having this issue.

I also want to point out that using Spot AF doesn’t cause the camera to focus more accurately. What it does do is cause the camera to evaluate a smaller area to analyze for focusing. That’s all. The only time I use Spot AF is for macro photography using a tripod with a geared head.

Re: EOS R - back-focusing slightly on AF

philobr — Sun, 01 Jun 2025 16:36:24 GMT

Can't adjust the R in the same way as others.

Re: EOS R - back-focusing slightly on AF

philobr — Sun, 01 Jun 2025 16:37:38 GMT

I used a tripod, exactly same settings. Focused on the top of a bottle with AF, then used peaking and guides on MF.

Re: EOS R - back-focusing slightly on AF

philobr — Sun, 01 Jun 2025 16:39:23 GMT

Was using a tripod. So if it's evaluation of position, then what should you use for AF in general photography? Wont be using a tripod all the time.

Re: EOS R - back-focusing slightly on AF

Waddizzle — Sun, 01 Jun 2025 16:47:53 GMT

“ I used a tripod, exactly same settings. Focused on the top of a bottle with AF, then used peaking and guides on MF. “

Let me put it this way. You have not provided sufficient information about your issue to offer meaningful advice.

No sample photo. No idea what your camera settings are, what lens you’re using, or what the shooting conditions are.

I suggest you follow Peter’s advice and setup a service ticket with Canon and let them calibrate your gear.