Canon R6 III 0 bytes in one out of three videos

[Ted M]

I've had my new R6 III camera for a couple of weeks now and can't work out why during a shoot about one in three videos that look like they are recording properly have 0 bytes and only a thumbnail when I take a look at the CFexpress card or download them to the computer. This seems to be a random failure and as my shoots are not repeatable I can't go back to re-shoot them. I've updated the firmware to 1.0.2 but that has not fixed the problem. The card is a 512GB Lexar Professional CFexpress 4 B with a 3600 MB/s speed and the two standard video settings I use are 4k 50 fps and 2k 150 fps.
Any ideas? Thanks in advance if you have a solution or workround.

 

[BlueBomberTurbo]

Haven't had this issue (...yet?), but I do know if you force the camera to shut down (usually a power loss or battery door opening), the video file will be completely erased and unrecoverable. Guessing it could also happen if the card door is opened, as Canon likes to kill everything if any door is open. Have you noticed any erratic behavior during operation?

 

[Tim Mayo]

Can you play the video back on the camera? If you can, it could just be an issue with the card reader that you are using or transfer. If you can recreate the issue then perhaps try a different card to rule that out. If it's still happening with a different card I'd be sending that R6 III back.

 

[Ted M]

Haven't had this issue (...yet?), but I do know if you force the camera to shut down (usually a power loss or battery door opening), the video file will be completely erased and unrecoverable. Guessing it could also happen if the card door is opened, as Canon likes to kill everything if any door is open. Have you noticed any erratic behavior during operation?

Thanks for your reply. No doors opening, just two or three video recordings that start off ok and are still showing the 'rec' icon on the screen end up with zero bytes in the file on the card. The thumbnail survives but nothing else. I can download these empty files to the laptop but there is nothing there.
I have twice noticed the red light in the front of the camera, usually solid when videoing, start flashing but that's it. I wonder if it is a connectivity fault in the camera.

 

[Ted M]

Can you play the video back on the camera? If you can, it could just be an issue with the card reader that you are using or transfer. If you can recreate the issue then perhaps try a different card to rule that out. If it's still happening with a different card I'd be sending that R6 III back.

Thanks for the thought. Each of the files that has not worked has zero bytes so there was nothing saved to the card and nothing to play back. It would be good to use another card to test if it is that but as I've never used CFexpress cards before I only have the one. I bought a top end card, a Lexar Professional, so I could rely on it but it surely does have to be either a camera or a card fault. I'll try sending video to the SD card instead to see if that still has the same issue.

 

[Dean Wilson]

I looked it up in the R6 Mk III Advanced User Guide and on page 403

 

[Ted M]

Thanks for this. I had wondered if it was because the camera was overheating although it seems to do this after a very limited amount of time, just minutes in. I didn't know the annoying front light was called the Tally Lamp so I've learnt something. I've managed to switch it off in Movie mode but it still lights up when I video in camera mode. Another disappointment.
I'll keep practicing to see just how long I have before the camera either stops recording video (up to six hours? Really?) because of overheating, both in Standard mode and High mode for Auto Power Off.
This helps me think there is nothing wrong with camera or cards but unlike the R6 MkI this beast cannot cope with prolonged use beyond about 20 minutes without a break. No good for my usual two hour model shoots but I'll just have to adjust somehow.
Thanks again for this info. It looks like you have given me the definitive answer I will now put to the test.

 

[Tim Mayo]

Maybe keep an eye on the temp warning display when recording to see that it's doing:

Canon : Product Manual : EOS R6 Mark III : General Movie Recording

Do you have the screen pulled away whilst recording? That can also help to keep the temps down.

 

[Ted M]

Thanks Tim. Once again, very helpful advice from a member of this forum.

I did once see the temp warning display but hadn't got a clue what it was at the time. One of my problems is that I am severely sight impaired so not only can I not use the viewfinder but I rely on the screen to compose images or videos and on AF to do the focussing for me. Spotting messages that appear mean I need to grab a magnifying glass to read them. As my only current genre of photography os nude models it is a bit disruptive to the flow the model has developed if I have to stop or grab something extra. It was never a problem with the R6 I but I do value the extra capabilities of the R6 III. I'll just have to make sure we take breaks every 30 minutes to let the camera cool down. I'll buy a second battery today too.
Thanks also for the thought of opening the screen to allow air onto the back of the camera. Not possible for me during photo shooting but should be possible at times when videoing, especially when using a tripod.
Once again, thanks for your advice and I think the help you and the other members have kindly offered has educated me to try and work around the heating issue from now on. I'll just have to make sure I have plenty of tea bags in stock.