Originally posted by PDL The file system used on SD cards is FAT which is prone to fragmentation by its very nature. Deleting images from the SD card has not been recommended as a method since the early days of digital. Even my old Toshiba (2002) digital camera manual suggested that deleting images off of the memory card (not a SD card) would eventually lead to problems. The software provided with the Toshiba camera would copy the images into its file structure, validate that the image was really there, then format the card.
SD cards are essentially hard drives, the file system is common to PC's and is based on Microsoft's FAT file system from back in the MS-DOS days. FAT32 and exFAT are newer variations leading to greater capacity, but they are still FAT systems. While using the SD Associations formatter is a good idea - for troubled cards - the best practice is to copy the images from the SD card (locked if your card reader supports it) and format the cards in camera. This was recommended to me in 2005 by the director of the digital lab at Santa Fe Workshops. I use a PC and they were using, and still are, Mac's.
2002? 2005? We're not in Kansas any more. :-)
No doubt that copying files in the safest way possible is a good idea.
Common sense and good data handling processes are key to ensuring your files are safe. (i.e. look up "3-2-1" backup policy)
*Myths and old wive's tales are not*
FYI, just for the safety conscious, Locking the card I useless, mainly because that is merely an optional software-enabled function of the device in which the card is in seated.
The slider has *no* hardware enforcement of protecting the card from rouge malfunctions (or intentional ones). It *can not* protect the card from being written or modified by any actions not completely under proper and strict control.
It's exactly like the punched holes on old floppy disks. i.e. remove the tape covering the hole and the protection is gone.
If anyone wants a *good* reason for not delete single files from their camera, just think battery life and time involved.
Extra cards are cheap.... Deleting files is expensive -- both with battery life and with the time it takes (i.e. the K1 is horribly SLOW at deleting files), and to delete files from both cards is maddening.
Formatting in camera uses a bit less battery than deleting all files. But still uses up your battery.
Format in the computer before you go out. It's MUCH faster. As a bonus, you even get to name the cards to your liking if that's your thing.