Hello, 5D MK3 users. Recently I shot a feature using 3 5Ds, one of which is a Mark 3. At the end of one particular day, I sat down to download all footage using a MacBook Pro and USB interface. When I spun up the 1st card shot on the MK3 (Transcend 64gb 400x), the Mac blackscreened and forced a reboot. After rebooting, 17 of the 38 video files and 4 out of 18 jpg/raw pairs only show 32kb thumbnails. (two video files, however, show 96kb and 160kb. Those are right above non-corrupted files.) all corrupted files are logged in chronological order beginning with the 1st shot. On the jpgs that are not linking, I see a line and a half of image at the top of an otherwise grey image.
Prior to spinning up the CF card on the Mac and it shutting down, I was able to play back some of the files on the camera. Now, when I insert the card back into the camera, the camera only shows a stamp-sized thumbnail and "cannot play video" error.
Searching around the internet hasn't offered a solid answer. There is no way to reshoot the footage, so I really need to salvage what we lost if at all possible. My sense is that the video files somehow disconnected from the thumbnail metadata, they still exist on the card even though the data cannot be read, and maybe there is a way to relink? Can anyone offer insight?
I didn't understand your post fully but to me it sounds like the CF card was partially corrupted because of the untimely reboot so now the only thing you can look to do is try and recover or rescue the card in question using one of the recovery services that specialize in flash media cards. I'd copy of all the "good" files of that card asap but make sure you don't write any new data to it.
Other people have reported success using these services on this forum but sorry I can't remember any service provider names but a search of this forum should turn up a few. The information is most likely still there but the index or "table of contents" to the data was corrupted.