topic Re: Mounted RF100-500mm lens is not stable in EF & RF Lenses

Mounted RF100-500mm lens is not stable

progfusion74 — Thu, 23 Oct 2025 18:48:04 GMT

I have an RF 100-500 lens that I use with an R5 mk2 (previously with a first gen R5). A couple of weeks ago I noticed that when I am holding the camera the lens actually moves after being mounted. I tried the lens on a different camera and it's loose there to and other lens are tight on the R5. One of the screws on the plate of the lens can't be fully tightened so it might be that. Anything else I could look at before I send it to Canon for repair?

Re: Mounted RF100-500mm lens is not stable

kvbarkley — Thu, 23 Oct 2025 19:21:39 GMT

Check the mounts on the camera and the lens. See if they are loose. You might be able to *carefully* tighten the screws if they are loose.

Re: Mounted RF100-500mm lens is not stable

jrhoffman75 — Thu, 23 Oct 2025 20:52:40 GMT

@progfusion74 wrote:

I have an RF 100-500 lens that I use with an R5 mk2 (previously with a first gen R5). A couple of weeks ago I noticed that when I am holding the camera the lens actually moves after being mounted. I tried the lens on a different camera and it's loose there to and other lens are tight on the R5. One of the screws on the plate of the lens can't be fully tightened so it might be that. Anything else I could look at before I send it to Canon for repair?

There are four screws holding the plate, so I wouldn't think one screw being loose would allow the lens to twist or bend relative to the mounting plate. Are the three other screws loose? Is the mount on the camera loose?

I would consider sending both to Canon.

Re: Mounted RF100-500mm lens is not stable

ebiggs1 — Fri, 24 Oct 2025 15:51:26 GMT

"I would consider sending both to Canon." Call 1 (800) 652-2666

Re: Mounted RF100-500mm lens is not stable

esimavi — Sat, 25 Oct 2025 23:46:19 GMT

yeah it moves around a tiny bit on mine. Hasn't bothered my footage much but I usually do videography.

Re: Mounted RF100-500mm lens is not stable

progfusion74 — Fri, 21 Nov 2025 01:01:18 GMT

Going to do just that. Thanks

Re: Mounted RF100-500mm lens is not stable

Tintype_18 — Fri, 21 Nov 2025 14:53:55 GMT

IMO, if a screw won't tighten, I suspect that the threads might be stripped out. Have it checked by a qualified tech.