Question about the mount on a Canon 5D IV

[Hector1970]

Hi All,
I bought a Fotodiox adapter (Exa to EOS) recently.
It connects fine to a 5D III and 5DSR but it won't screw into the 5D IV.
Is the mount different in the 5D IV does anyone know?
I can't turn the back of the lens into the mount. It doesn't twist in for some reason.

 

[Mt Spokane Photography]

No difference in the mount, except it might be newer and tighter. Canon holds the mounts to extreme tight tolerances, just a few tens of thousands make a huge difference. I'm not so sure about the Photodiox's tolerances, I have some of their adapters and they tend to be overly tight on my EOS cameras, still, I manage to get them to work.

 

[Hector1970]

Thanks Mt Spokane. I was surprised. It fitted to a 5DIII mount no problem but can't twist on a Mark IV.
I never had a lens which did that

 

[Mt Spokane Photography]

Thanks Mt Spokane. I was surprised. It fitted to a 5DIII mount no problem but can't twist on a Mark IV.
I never had a lens which did that

Camera mount tolerances are a bigger issue than is apparent, simply because Canon and Nikon are fanatic about their tolerances. Even so, I occasionally see a post from someone who bought a new lens that is extremely tight. The tolerances have all lined up to the worst case. They exchange it, and all is fine. Canon had a patent for camera mounts a year or two ago that was intended to reduce wear on the camera mounts, which was noted as the issue being addressed.

 

[LonelyBoy]

On the converse, my 5D3 is a touch loose, so all lenses can rotate just a touch on it. Drives my OCD up the wall, but works fine. And I don't change lenses as much as most of y'all must.