EOS R5 - the ISO continues to change even though I'm shooting in Manual Mode/ER 70

[shayscala1107]

Hey guys, I have used the R5 for dozens of weddings, but this past Saturday, my ISO continuously changed even though I was shooting in Manual Mode.  This is the first time this has ever happened.  

Also, myself and my 2nd shooter were BOTH using 2 different R5 cameras and were both receiving the ER 70 error. 

Any ideas on what in the world is going on?  The wedding on Saturday was ROUGH because of these problems!

Thanks for your help!

[Tronhard]

At the risk of asking a silly question. Are you shooting in Auto ISO while the camera is in M mode?

[shayscala1107]

Yes!  I have looked in both places already.  

[Tronhard]

Thanks for your response, but I'm not sure what that means.  If you are shooting in Auto ISO, that will continue even in M mode.

[shayscala1107]

I am NOT shooting in Auto ISO!  For instance, I am shooting in Manual Mode with 1600 ISO and then it continues to change on me on its own.  I am shooting the same way I have been shooting since I got the camera and this has never been an issue.

[Tronhard]

Thank you for clarifying that and while I appreciate your are frustrated, please realize I am trying to clarify the facts and your response of Yes! to answer my question could be interpreted that you are in fact, shooting in Auto ISO.

[stevet1]

shayscala1107,

I guess I would have 4 questions:

1) When you say the ISO changes, does it consistently go in one direction?

Does it always go up, or does it always go down, or does it fluctuate?

2) Have you tried setting a different ISO, like ISO 800, and does the same thing happen?

3) Is the lighting different from shot to shot when you see this behavior?

4) Do you by any chance have a maximum ISO set in your menu? 

As far as the Err 70 goes, I'll leave that to people who know more about those things.

Steve Thomas