Canon Mark IV won´t take pictures

[BjornThorkildse]

My Mark IV worked fine yesterday and tooday on a shoot it just stopped taking pictures when the AF is yurned on the lens, and when I switch it to MF it takes pictures! When I tried to use the auto focus nothing get in fokus, it just kind of give up and leave everything blurry and out of focus! Anyone else have this problem?

[Waddizzle]

Is that the 5D Mark IV?  Which lens are you using?  There are a few reasons why a DSLR "won't take pictures."  How experienced are you with using DSLRs?  The common cause for a camera to not take a photo is operator error.

1. Insufficient light for the camera to focus, which seems less likely with a 5D4.
2. Subject is too close and within the MFD, minimum focusing distance, of the lens.
3. Some lenses have focusing mode switches, which can significantly increase the MFD.
4. Not enough contrast at the selected AF point.

No doubt, there are other reasons that can be cited.  Of course, you could really have a camera failure.