Recap for my new 60D

[Bruce Foreman]

SanDisk is one of the most reliable brands of media cards out there. Costs a bit more, but B&H has some pretty good prices on them right now (I just picked up a 16GB - been using 8GB in my 7D) and a couple more 16GB Class (10) SDHC cards.

It's important to reformat your media cards each time you copy your files off to a computer (once you are sure you have the files safe in two separate locations - I use 2TB external drives in pairs). This keeps the card's format "fresh" and makes for most efficient writing of data to the card. Even SanDisk will eventually encounter problems if you simply "erase" files although it may take awhile.

I've read a couple of accounts of corrupted cards where the operator simply put a new card in the camera and never formatted it in camera. Kept deleting individual stills and video files until one day he started getting errors.

[Jordan Hooper]

Bruce, can you cite some information about reformatting vs erasing keeping the cards "fresh?"

The reason I ask is because I use Magic Lantern when I shoot video and I erase rather than reformat so that I don't have to reinstall ML. I'd like to know in more detail how this might be affecting my card.

[Bruce Foreman]

Reformatting totally "reorders" the media format where erasing merely tells the "file allocation table" it can reuse the portion the file previously occupied. At first the file is mostly left intact, part of the filename is replaced with other characters. Over time the constant erasing/deleting of files leaves fragments of files lying all over the media and "bargain brand" media is increasing susceptible to corruption as this goes on.

Even SanDisk & Hoodman media can eventually get corrupted.

I don't use ML so I cannot address your situation.

[Tom Hardwick]

There's compelling evidence to suggest that reformatting a card considerably shortens its life expectancy, so this is a consideration to be recognised, if not acted upon. Of course shortening a card's life to 10 years is probably ok for most of us.

[Taky Cheung]

I think that fragmentation problem is more for harddrives for computer system instead solid states memory card for camera. For computer daily operations, there are many big/small files created and deleted all the time. So after many saving/deleting operations for a while, there will be lots of "holes" in the memory allocation. Next time for larger file to be saved, it will be split into smaller fragments that cause a hit in performance. For computer harddrive to restore performance, that's why we run defrag regularly.

For a freshly formatted SD card, all the large mov files saved and later deleted. There shouldn't be any issue with the FAT.

:)