topic Re: RF 100mm f2.8 macro lens serious focusing issues in EF & RF Lenses

RF 100mm f2.8 macro lens serious focusing issues

SubDriver — Tue, 09 Dec 2025 03:47:14 GMT

I recently purchased a RF 100mm f2.8 macro L series lens. I'm using it with a new R5 mk II. The lens moves out of focus with no input from me. When I try to focus on an object with sufficient light and contrast the lens doesn't move. Using the manual focus mode to dial in focus, then using auto focus helps but even that is a hit or miss proposition.. It's a time consuming, frustrating process. I've never experienced this issue with any lens/body combo I've used over the yrs. Either something is seriously wrong with the lens or I'm missing a setting somewhere.

Anybody else experiencing this problem? Any advice on how to remedy this situation would be greatly appreciated.

Re: RF 100mm f2.8 macro lens serious focusing issues

Anonymous — Tue, 09 Dec 2025 10:28:08 GMT

Set preview AF to disable, lens drive to on

Re: RF 100mm f2.8 macro lens serious focusing issues

ebiggs1 — Tue, 09 Dec 2025 15:22:53 GMT

"When I try to focus on an object with sufficient light and contrast the lens doesn't move."

Make sure you are not too close to your subject. It is about 10" but if you are right at the 10" limit it may still find AF difficult to achieve. The in and out is probably the lens hunting for focus which it can't do if you are too close.

Re: RF 100mm f2.8 macro lens serious focusing issues

SubDriver — Tue, 09 Dec 2025 18:38:25 GMT

Thanks for your help. That doesn't seem to be the issue. When the lens doesn't focus it is wildly out of focus. I've tried to focus on object 10' away ( lens doesn't move, still just an out of focus blob in my vf) Then I move to a macro shot approx 12" away. Lens doesn't move, still OOF blob. After moving lens around to focus on different items occasionally the lens will begin to focus properly. It helps if I focus on subject manually. Then the lens will do its job (focus) for a while, then reverts back to OOF. This is the best I can describe what is happening with the lens. I'm puzzled and frustrated.

Re: RF 100mm f2.8 macro lens serious focusing issues

SubDriver — Tue, 09 Dec 2025 19:06:12 GMT

Thank you so very much! I believe your advice solved the focusing problem. After setting continuous focus search on, as you suggested, I wandered around the house and backyard and the auto focus seems to be working just as it should. I'm a happy camper.

Re: RF 100mm f2.8 macro lens serious focusing issues

Anonymous — Tue, 09 Dec 2025 19:15:13 GMT

It's a problem with mirrorless, if there's not enough contrast it can't focus, long lenses, big apertures and macro make it worse.