My 5D Mark IV seems to randomly "automatically stopped recording" video when using various fast SD cards. It's strange, it might record for several minutes long clips without any issues but then suddenly stop on it's own on a new clip after a few seconds. After that it would appear to be stuck "writing" as the red LED indicator keeps lit and the rest of the camera is unresponsive for a while. Have even sometimes had to pull the battery after being nonresponsive for a while.
Now these are all fast SD cards of various brands and they've all exhibited this behavior, but again randomly. It doesn't do it on the first video I start shooting on so I've always thought that maybe only some brands/speeds work while others don't, or maybe it depends on the video recording mode/settings and what I'm shooting (like if it's busy/has a lot of info to process it can't keep up).
After multiple shoots I've seen this happen and have had to revert back to only using CF cards to be safe.
Cards I've used are SanDisk Extreme PRO SDXC, Transcend and Sony, all of them Class 10, UHS-I U3 with high rated speeds. All bought from reputable retailers like B&H, Adorama, etc and all of them have worked flawlessly on other cameras like Sony and Panasonic shooting 4K video. On my Canon 5D Mark IV I wouldn't even be shooting 4K, am only shooting 1080p footage and this still happens. I remember it happening even on my old 5D Mark III with some SD cards as well.
Are the U3 SD cards just not fast enough for Canon even though they work perfectly on every other camera? Am I just unlucky and got 2 5D bodies in a row that have randomly defective SD slots?
Would appreciate any help!
Card complexity is a pain with the various standards, the questionable rating systems used by some purveyors (i.e. transfer speed instead of the all critical write speed for our tasks), and the problem of counterfeit cards and those that aren't really what they claim to be (i.e. Cfast 2.0 cards using slow memory that provides lower performance than a regular CF card). During extended video recording the camera and card will have a large temperature increase and lower quality cards that work OK in intermittent usage may become flaky as their temperature increases.
I picked up a Cfast 2 card for my 1DX M2 which is required for recording high frame rate 4K video but later decided that for my use it made sense to pick up a dedicated camcorder for video and my Canon XF-400 only requires a fairly low cost U1 or U3 speed class SD card for 60 FPS 4K recording and it doesn't have the 30 minute time limit since it doesn't have to masquerade as a DSLR for taxing purposes.
The 1DX M2 does great video but the camera form factor that I like so much for still photography drove me crazy when trying to capture sports action using the rear display screen of the 1DX. The XF-400 rotatable side mount display works very well but most of the time I use the camcorder's viewfinder display-probably an artifact of many years of still photography. Not being able to use my EF lenses for video was a drawback but I don't care as much about video quality compared to stills and the wide range zoom built into the camcorder and the XF series met my needs better than the EOS cinema line.
I have come to the conclusion that I will not buy a new camcorder for some time, as there is a constant shifting and movement with camcorder technology. I use the 1DX MII and 5D MIV mostly for talking head interviews, gimble shots or slider shots. If I need anything more thant that, I will now rent. I do like the XF400 for run and gun shooting, but if my clients want a higher end look, I will use a C200, which produces some amazing images with the RawLite format. At least I can use the CFast cards I already use for the 1DX. A big portion of my business revolves around still photography, so the DSLR route still is a sensible choice for me.
Unlike the 5D MIV, I did notice that the UHS II cards do actually work, though I'm not sure that it is utilizing the card as such. Do you have any insight on this as the Canon manual is a bit vague and makes no mention of UHS I or II.
As far as I can tell the XF-400 won't use the UHS-II card as such and you are right about the lack of information. Although it is difficult to get a clear view into the card slots it appears the additional connectors that work with the UHS-II are missing so the better card would just be used in compatability mode. Given the file compression it doesn't seem to need anything faster than what a good UHS-i class U1 or U3 card can deliver.
The XF-400 is the perfect size for me to use for mostly handheld with a little tripod use for sports. It has nice balance but I definitely am more of a still photography type and I haven't delved as deply as I should into using all of its capabilities. My 1DX 2 is hardly ever in full auto mode while the XF-400 has spent most of its time there-something I need to change.
I, too, am having this problem on my 5D Mk IV. It's also been a matter of inconsistency and not understanding the cause of the problem. There are times when I can record for over 12 mins with no problems, and then there are times when after 3 seconds, it stops. It seems that turning the camera off and back on is the only consistent "fix" for the problem, but at some points, it comes back, and I can't seem to figure out what causes it to return. I am recording to my SD card which is a SanDisk Extreme PRO 95MB/s SDXC V30 128GB card. Again, I would also suspect the card except that there are times when it works just fine. So just adding my two cents to this thread.