Canon 7d error message. “cannot playback file”

[John Young]

Jose,
I have been using the 7D for about 3 years and I have had this happen on two occasions. What I think is the culprit (or at least the catalyst) in my cases, is when you stop recording and start recording too fast. I think the camera needs a few seconds to write the lead on the file you are recording to, and it you press START RECORD, right after STOP RECORD, I think the camera has errors writing the lead out for that file.

The good new is that it is possible (although kind of expensive) to record the entire files that are corrupted. These guys have saved me a few times. https://aeroquartet.com/

John

[Jonathan Ziegler]

I have had that issue, but not in the camera. The camera battery died while we were shooting and the video stopped. I could play the video back on the camera, but not on anything else. I was able to convert the files in MPEG Streamclip beta (Compressor wouldn’t work) to ProRes and they played fine. I have lost videos on the camera, too (they just seemed to disappear) and I’ve had videos freeze the camera. In all cases, removing the card, dumping the contents, and formatting the card allowed me to work with files on my machine.

I’ve also heard this will happen if you haven’t formatted a card in a while, but I can’t verify that since I always format my cards. I guess it has to do with the volatility of flash memory and a low-level format is supposed to fix (or help) that. Furthermore, it won’t hurt the card to reformat it (that I know of) and deleting can leave bits of files on the card which can cause problems down the road. After a few months on the same card, I’ll also use disk utility to write zeros to the card (takes no more than 20 minutes using my laptop card reader for a 16GB card). Do a “DoD 7-pass” once a year, but skip the 35-pass unless you are really paranoid or a covert operative in which case you have much larger issues. 😉

I use dozens of (SD and CF) cards with my 7D and T2i cameras from almost as many manufacturers. My secret is to always do a low-level format on a fresh card, always dump cards ASAP, avoid filling cards as much as possible, use a new card for each new scene, shoot, location, etc., always use class 10 SD cards no matter the brand (for CF cards, use the fastest you can find no matter the brand), I rarely use anything larger than a 16GB card, remember to lock your SD cards when finished, put them in their case or holder when not in use, remove cards (and batteries) from the camera when not in use.

There are only a couple flash memory makers in the world so everyone has theirs made by the same group of manufacturers. The process isn’t a big mystery and the people that make the off-brands are the same people who make the big brands – if you had the equipment, you could make flash memory yourself. I’ve had the same issues with every brand out there so buying by brand doesn’t help. By using the rules above, I’ve minimized most of my issues – in fact, formatting instead of erasing has been the biggest help. Too bad good card handling won’t improve my shooting! 😉

Hope that helps. 🙂

Jonathan Ziegler
https://www.electrictiger.com/
520-360-8293

[Jose Santiago]

Great response Jonathan. I actually have NEVER formatted my CF cards since I got them about 2 years ago. So I guess I will be doing that asap. Thanks for the advice, and hopefully that clears up those playback issues.

Jose