R5 lens adapter and 24-105 canon lens won't recognize AF

[levinelaw]

My Canon R5 with a Canon lens adapter works well with my Canon 70-200 and a Tamron zoom, but my Canon 24-105 lens only shows up as manual and AF won't work. Thoughts?

[shadowsports]

Greetings,

Please confirm.

R5 with Canon brand EF to RF adapter. Your 70-200 gen x and Tamron Zoom work correctly, but your 24~105 f4 gen unknown does not?

Sounds like a lens communication issue. Is this a lens you owned previously? Or new to you? Have you tested the lens on another un-adapted body? Does it have updated FW available possibly? Canon lenses don't normally require FW updates, but occasionally when something is discovered, or for compatibility they might receive one. Check its terminals and clean. Ensure the AF/MF switch is functioning. If all else fails and it checks out on another body, you can contact support and inquire what options you might have. Again, not knowing age, condition or history, etc.

[levinelaw]

Thanks for your reply. The lens has been owned by me for a few years and AF worked fine on the 5DIV I traded in for R5. I will have to try on an EF body camera. I don't know anything about FW updates!

[shadowsports]

Greetings,

Did a quick check and do not see any FW for the 24-70 f4, of which there was only 1 variant.

Used in conjunction with w Canon EF to RF adapter, it should function on an R5.

Canon does offer a Maintenance / Cleaning / Inspection for $69. Might be worthwhile of you believe the lens is having issues.

Canon Support | Canon Maintenance Service | Canon U.S.A., Inc.

[levinelaw · Accepted solution]

Thanks again for looking into this. I called Canon and they suggested cleaning the contacts with an alcohol water mixture which I tried. Screwed it into the adapter and now it works. I think the original problem may have been I needed to turn the lens more fully into the adapter as it turned to a point of resistance and I had to turn a bit more. Problem solved!