Why is my SD card filling up too fast?

Question

I have a Canon Rebel T3 and a Lexar Platinum II 8 GB SDHC class 6 card.

I can only fit about 180 photos on this card that are roughly 5 MB each. Unless my math is really bad, that's only about 900MB used, so I should still have 7 GB left - but I don't.

When I plug this card into my computer and dump all the photos off, it says it has 8GB capacity, but every time I go out to shoot photos the same problem comes up, and I'm limited to under 200 shots and then my camera tells me the card is full.

Can anyone tell me what might be causing this, and any suggestions to help resolve this issue would be appreciated.

Answer 1

There is likely a hidden folder on the card somewhere that is using up your space.

Using a utility like DaisyDisk on the Mac will help identify the missing space, and let you clean it up.

I have found that some cards have ".Trashes" folder that gets created and keeps copies of a bunch of junk you've deleted in the past. removing this folder will let you reclaim your lost space!

Hope that helps!

Answer 2

Macs place a hidden file and folder on mounted volumes. The file is always small but if you delete files from the card using Finder then they will end up in .Trashes until the the trash is emptied. Some other possible reasons might be you have done some kind of move or copy/delete, or copied something to the card, or maybe you never formatted the card when you first used it in this camera.

Best way forward is to save everything from the card and reformat in camera, then write protect the card before connecting it to any computer especially a Mac.

Answer 3

Ι had the same issue. A 32 GB card showed 152 photos left (!) while normally it is more than 1200 (Eos 6D - same issue with Eos 600D). I erased all the photos from the card which was inserted in my Macbook Pro and in the Trash all photos appeared as locked items, although I never protected them. Formatting the card was the simple and easy solution.

Answer 4

There are three possible most likely explanations.

1. As others have noted, there are hidden files somehow taking up space. Reformatting should fix this.
2. Some sort of corruption. This actually comes in two flavors:
   • Corrupt filesystem, no real problem: Again, reformat and the problem goes away.
   • Lower-level flash corruption. Reformatting won't help, and may in fact mask problems temporarily. Best fix is to throw it out and get a new one.
3. If this card was this way the first time you used it, odds are you have a fake. The easiest, cheapest way to fake cards is to take one of a smaller capacity and modify its firmware so that it lies to the computer and says that it is a much larger card. Use F3 under Linux, Mac, or Windows to verify if this is the case.