This is a general workflow question (also) but I'm posting it here because it involves Canon cameras.
Our production group is recording video to SD Cards using a VIXIA HFG30 and a EOS Rebel T3i. We want to back-up our footage using external hard drives and re-use our SD Cards. On our very first shoot we lost some footage shot on the Rebel. I believe it is because we took a Sandisk card which had been used in VIXIA, formatted the card in the Rebel (I did not select "low level format") and we continued to shoot with the Rebel.
On the day, we checked playback on the Rebel and saw the recordings we expected. In the edit suite, the memory card mentioned above appeared to be damaged. Our editing PC running Windows 10 can see the file structure and the files on the SD Card, but we cannot playback the .mov files and they will not transfer to the PC (either via import from NLE nor using Windows file transfer). After we tried reading the damaged SD Card on the PC, the card no longer reads on the Rebel. We have had no issues with other SD Cards used on the same day.
It would be amazing if we can recover the damaged files, but this post is looking for advice on how to standardize our workflow to limit (or maybe even avoid) losing footage.