Canon 5D IV movies with half frame missing

[deecee2]

Hi

When i tried to playback several movies I'd just shot on the camera, the camera playback suddenly stopped and went back to the start of the clip. 

After i downloaded the movie to my computer and went through the movie frame by frame, i saw that at the point the camera stopped playing the video, there was a frame in which the lower half was blurred and pixelated in to tiny squares.  Clearly the camera's playback can't cope with this corruption and stops playback.

It now happens with every movie i shoot and I've found that these corrupt frames happen randomly throughout every clip.  Sadly all the videos are unusable.  I have two new fast cards in the camera and it occurs if i record on either.  I've also older tried slower cards which i've had no problems with and it happens with them too.

I feel it's not a card issue but a camera issue.  Oddly I've searched the web and not found anyone else with the same problem. 

Perhaps there's someone out there who might be able to help or seen this sort of thing before

thanks

d

[TCampbell]

Why do you feel it is not a card issue?

[deecee2]

Hi Tim

Simply by elimination.  I had two new cards in the camera, a UDMA 7 and an Extreme Pro disc and both had the problem. I then tried two older cards that i'd never had a problem with and they too had this glitch after i shot a new clip.

I'd formatted the new cards before putting them in the camera and have done so again after seeing the faulty frames, but the problem persists.

What do you think?

[deecee2]

Heres a sample frame of what's happening

[wq9nsc]

Have you tried shooting at a lower video resolution/frame rate to see if the problem is present?  It takes a very fast card to keep up with 4K at a high frame rate.

My 1DX Mark II requires a Cfast 2.0 card for the highest frame rate at 4K while my XF400 (Canon video cam) requires a UHS class 3 card for 4K mode and it has a slightly lower pixel count and a more effecient compression algorithm than the EOS cameras in 4K mode.

Note that there is real world variance between rated and actual sustained card transfer speed and some of the review sites do a good job of measuring this specification.  There are also a lot of counterfeit cards out there which have much lower performance than the real article;  a couple of years ago I had to return a couple of cards that were clearly counterfeit SanDisk to a large online purveyor and I ordered and received real cards from B&H to avoid other counterfeit issues.  Although it doesn't apply to your 5D Mark IV when I started looking for Cfast 2.0 cards for my 1DX M2 I found that there are cards out there in the Cfast connector format using regular CF card memory which is why some of the Cfast cards are far less expensive than those that actually provide Cfast card performance.

Rodger