Canon EOS R5 randomly changing f stop

[snaphappy19]

I've been shooting with my Canon R5 for two years now, and in the last six months, I will be out on a shoot, and the f stop will just randomly change.

I shoot in Manual always, and I set up my camera to the settings I like, and then leave the camera on. I'll stop to talk to my client and pose them and then lift my camera up to my face and take the picture. The exposure will be WAY off, and I'll look at my settings. The f stop will have randomly changed to 8! I NEVER shoot at f stop 8. I shoot all my portraits at 2.8 or 3.2 (I'm shooting with a 50mm 1.2 lens.) I have no idea why the f stop will just randomly change during sessions, but it is driving me crazy!

I reached out to a local FB photographers' group, and there is one woman who is experiencing the same thing with her R5. 

Has anyone had this problem? Was there anything you tried that fixed it?

BTW, I updated my firmware to 1.9.0, but the Canon rep I spoke with said the firmware is not going to fix this issue. 

Thanks for any advice or suggestions!  

[Waddizzle]

Welcome to the forum!

You are not the first to post similar comments about exposure settings changing when they are shooting in M mode.  We eventually figured it out, but each case was unique.

What lens are you using?

Which control do you normally use to adjust Av?

Can you post an image that demonstrates the issue and include the EXIF data?