Canon 5D Mark IV issue in manual

[Ethover]

New to the forum, and thanks in advance for the help. 

Ive got a Canon 5D mark IV, and have had it for a year or so. All firmware is up to date. I normally shoot in manual mode. Recently, when I shooting in manual, I cannot operate the shutter without the aperture adjusting at the same time. The aperture lock on the camera body is NOT enagaged. Furthermore, I’ve reset the camera to factory settings, and made sure to renew the firmware. (It was already up to date). I’ve taken the batteries out multiple times. 

Its operating like its on the AV setting, despite being set on M. 

The end result, is nothing changed. I simple can not operate the camera in manual, with the ability to change shutter speed while the aperture stays. 

I guess, my first question is, has anyone had this same issue? And if so, how did you change it. Or, do I have a bad dial for the settings between AV and Manual? 

[wq9nsc]

You have safety shift turned on, It is Cfn. 2 for my 1DX 2 but check your manual to see which custom function it is for the 5D4.  When ISO is fixed (not auto) and you are in M, Tv, or Av modes with Cfn. 2 enabled then it will automatically change one of the set parameters to achieve the standard exposure.

Rodger

[Ethover]

Thanks for the idea, but that’s not it. Mine is turned off. 

[wq9nsc]

Odd,  What mode does the status window on the camera indicate?  Is it showing you are in manual?

Rodger

[TCampbell]

Like Roger, I'm wondering if the camera thinks it is in Manual mode.

If your rear-screen is set to show basic camera info, you should see the letter in the upper-left corner indiciating which mode you are using (or at least which mode the camera *thinks* you are using).  

While I've never run into this on a 5D IV, I recall that just occasionally a 6D would get confused... the physical mode dial would be set to one mode, but the info screen would show it was in a different mode.

Make sure the mode dial and info screen agree on the mode.

Fixing it may require it going back to Canon.