5D Mark IV video automatically stopped recording on fast SD cards

[chansjsu]

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! 

Thank you!

[Waddizzle]

Are you performing a low level format on memory cards before you use them?  Good, I though you were, because that is most likely not the issue.  

Because of the file system used to format most memory cards, there is a 4GB limit on the maximum file size.  At maximum video resolutions, this can result in video clips that are only several minutes long.  Some DSLRs will stop recording, while others will try to keep recording by storing video data to a new file.

Sometimes, it takes time to write a 4GB file.  Your camera may show "buSY" on its' display until the 4GB file is fully written.  Meanwhile, if you are still recording video while the 4GB file is being written, then everything can slow to a craw.

The above image is a screen shot of the instruction manual for an EOS 80D, I think, but it is typical of nearly all Canon DSLRs that are limited to maximum file sizes of 4GB.  Be aware that most DSLRs, not just Canon's, may also be limited to a maximum recording time of 30 minutes in a single video file, too.

[chansjsu]

Hmm, I haven't done low level format, just the regular quick formatting on SD cards.
As for the 4GB limit, that's never been an issue as I know with the 5D Mark IV and I think even since the Mark III they've automatically rolled over into a new file after the 4GB. The only other times I know it'll stop if it reaches 30 minutes, which is normal behavior.

Again I've only seen this happen only ever with SD cards. CF cards have never stopped recording on me ever. And again with the SD cards, it doesn't happen consistently which is why I haven't been able to pinpoint the exact cause of this issue.

[TCampbell]

Are any of these "MMS" cards?

Here are the specs for card types supported for the 5D Mk IV (taken from Canon's specifications page):

Recording Media

1. CF card 
   • Type I drive (Type II and Microdrive non-supported.)
   • UDMA Mode 7 supported.
   • CFast cards cannot be used.
2. SD, SDHC and SDXC memory cards 
   • UHS-I supported.
   • MultiMediaCards (MMC) cannot be used (results in error).
   • UHS-II not supported. If a UHS-II card is used, it may be slower than a UHS-I (depends on the card specifications).

Note that you can use other SD cards and they will "work"... but they may not perform as needed.

[chansjsu]

MMC cards? From 10+ years ago? I've listed the brands/types of the cards in my original post. Here are pictures too. They're current UHS-I SD cards that are bought from reputable retailors (so they very likely aren't fake/copies unless B&H got a bad batch). 

As you listed, UHS-II isn't even supported so I haven't bought those newer/faster speed SD cards since they aren't even supported. And again my UHS-I cards all work perfectly fine on every other camera I've tried them in.

[Peter]

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@chansjsu wrote:
Hmm, I haven't done low level format, just the regular quick formatting on SD cards.
As for the 4GB limit, that's never been an issue as I know with the 5D Mark IV and I think even since the Mark III they've automatically rolled over into a new file after the 4GB. The only other times I know it'll stop if it reaches 30 minutes, which is normal behavior.

Again I've only seen this happen only ever with SD cards. CF cards have never stopped recording on me ever. And again with the SD cards, it doesn't happen consistently which is why I haven't been able to pinpoint the exact cause of this issue.

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Then it is time to do a low level format.

[TCampbell]

Those look to be valid card types.

A UHS-I card should have the SDXC or SDHC logo with a roman numeral "I" after it  (see samples logos here: https://www.sdcard.org/developers/overview/bus_speed/ )

Also, on the back side of the card, a UHS-I card will just have one row of gold contacts on the leading edge.  A UHS-II or III card would have a 2nd row of contacts (photos are at the above SD-card standard website).

I would do a low-level format.

Also... is there any chance you've used this cards in a different camera before using them in this camera?  Most cameras lay down a file structure after they do the format and the file structure is specific to camera model.  So it's generally not a good idea to swap cards between cameras unless you reformat them so they get the correct file structure layout on the card.

[chansjsu]

I will try and test that out. What does low level formatting do exactly and why does not doing so cause these problems with SD cards? It doesn't seem to take much longer than formatting without that option. However on other forums there are comments about low level formatting shortening the cards life.

One thing that was awesome with Sony cameras for example is if you use a slower card, if you are shooting a particular video setting that requires a certain speed, it will tell you before you start shooting if the speed isn't sufficient. I wish our Canon cams had this capability.

[chansjsu]

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@TCampbell wrote:

Also... is there any chance you've used this cards in a different camera before using them in this camera?  Most cameras lay down a file structure after they do the format and the file structure is specific to camera model.  So it's generally not a good idea to swap cards between cameras unless you reformat them so they get the correct file structure layout on the card.

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Yes, I have swapped the SD cards between cameras before, but before using them I've always formatted them on each camera to be safe. Only Canon has the low level format option which I've never used before, just the default formatting. If this truly is the cause I guess I will just have to make sure it always formats low level every time then. 

I also remember my issue has popped up before even with a brand new SD card that was never used in any other camera previously but again I didn't do low level format. 

Hopefully this is the answer and I'll never have to encounter this dreaded problem ever again...

[TCampbell]

The main difference between 'low level' vs. a quick format is that the low level actually does test the card.  A quick format assumes the card has no issues and simply puts a filesystem on the card with the basic directory structure the camera expects but it doesn't actually test any of the empty space to make sure it's all fine.

Low level formats typically erase, write, then read-back to verify that what it reads back actually matches what was just written to that location (e.g. it can detect errors that the quick format would miss).  

Also, if there is an error, filesystems have the ability to mark blocks as "bad" -- so that way it wont attempt to use that block again (and you don't have to toss the card in the trash bin).

You shouldn't need to do low-level formats every time... but it's always a good idea to do a low-level format at least once with each new card.