Hi

I currently use a Canon R5, RF/EF adaptor, 1.4x extender (Mk III) and a 400mm f4 EF lens. I am having what I think are software glitches between the camera and lens, where the camera frequently locks up when I try and focus on the subject. I have to temporarily remove the battery to reset the system. I have tried two different extenders and two different RF/EF adaptors with no success. I am thinking that I am having software problems because the camera is communicating with the lens via an adaptor and extender, I was wondering if anyone else has experienced anything like this with the new R series mirrorless cameras? Today I am going to test the setup without the extender to see if the problem goes away, but I find in the field that 400mm zoom is not enough. I don't really want to buy a new RF lens, but I am thinking that is what I might have to do.

Geoff Dennis

Hi Geoffrey,
Thanks for sharing and sorry to hear it’s been playing up.

I’ve not heard many issues by others. What brand and model is your lens? There are many people using the Rf-Ef adapter without troubles so I’d be surprised if that is the problem. As you say you’ve tested it with other RF/EF adapters and got same result?

If you haven’t yet checked you’re running latest firmware on the r5 , definitely give that a try. R5 firmware Link here

Finally, and Probably the least likely, is there any skin-oil/debris on any of the the lens mount contacts? With the adapter, extender and lens, there are now 6 contact points. If any are dirty try a cotton-tip/ear bud, dipped in a mixture of 50% metho 50% water and it should clean them up. Allow to completely dry before reassembling and testing.

Even if your lens isn’t a canon one, you could try contacting canon for advice before splashing out on a new lens (unless you want a reason to buy something ) Right down down the bottom of their support page they list a phone number 1300 460 738, and email contact page

Let us know how it goes. Sharing our experiences here benefits everyone navigate these challenges and pitfalls easier.

Hello Geoff,

Are you running the latest firmware on the R5? It should be version 1.6.0 released on 15 July 2022 and can be downloaded from the Canon Australia website. Having said that, I occasionally see glitches with the R3 and R5 that seem to be associated with the EF-RF adaptor + 1.4x III extender that can usually be fixed by attempting to rotate the connection back and forth within the slight mechanical tolerance available. I think there is sometimes a loss of good electrical contact through the adapter and extender. Maybe the electrical connections need a wipe with a clean cloth to remove dust.

I agree 400 mm does not provide enough reach, I find 400 mm f/4 DO II + 1.4x III with the R5 is a good combination. Others are getting good results with 500 mm focal length.

Cheers,

Ian

Thanks Ian and Desmond

My software was 1.3 and I have now updated to 1.6. My lens is Canon 400mm f4 DO IS II USM. I will now clean the connection contacts and take the camera out for a test run. I really appreciate your advice on this and hopefully now my equipment will not malfunction every couple of minutes.

Regards
Geoff Dennis

To close out, my equipment is now working perfectly, and to top that off, managed to get a nice picture of a Lewin's Rail when testing it this avo.