To Format or To Delete
Once in a while, we have Beginners ask about the best way to make their flash media card ready for next use in the camera.
- They wonder whether they should delete the photo files using the delete menu of their camera vs delete feature of their computer.
- They wonder whether they should format the card on their camera or format their card on their computer.
Deletion does not re-draw / re-initialise the FAT
- Deletion marks the relevant filename entry(s) in the Directory Table as "killed" but does not necessarily flush the filename nor the FAT entries. As you write files onto the card, these entries will be over-written.
- Formating re-creates thefile system. This ensures that at this point in time, there is no corruption of the FAT or the DT.
- You can "Delete All" using the camera and still have files that the camera does not understand or know about on the card. You could put music, office documents, whatever, on the card and "Delete All" from the camera might be blind to that.
- If there was accidental corruption of the FAT / DS, deletion does not attempt to repair the corruption.
- Deletion of all files is slower because it marks each entry labouriously, one by one. Quick Formatting simply wipes the FAT and DT.
- In some scenarios with some computer operating systems, there is additional information that the computer stores on any media. A hidden Recycle Bin folder could be one. Mac OSX file structure forks could be another. The camera may be blind to these files and structures and deletion or operations by the camera would be blind to these structures. Meaning that your card could have hidden stuff on it taking up space and the camera would not be able to manage that without a Format
- If you are prone to mishaps and every photo file has been deleted on the card using "Delete", there is a high possibility that computer recovery programs can undelete / undo / recover your photo files. The ability to recover after you have carried out a Format is much lower. For more reading, see Data Recovery
The Format command on the camera is likely a Quick Format
- Data Recovery might still be possible to some extent if the same card has not seen new files, has been formatted on the same camera.
- A Camera Quick Format shouild not contribute to wearing out your card or damage your card.
Formatting / Data mishaps on the computer could cause issues
Although there is the general concept and even standard on what the FAT and filesystem is, each type of computer and camera may approach the implementation in different ways.
- FAT is just not FAT - there is FAT16, FAT32 and other lesser known FAT standards.
- The Olympus / Fuji xD cards had digital signatures in on the card. If these signatures were unexpectedly wiped by formatting on the computer or you had an accident with premature removal of the card from the card reader etc..., you could have card that was physically able but the camera would refuse to recognise it.
Storage Media are not Forever
The views and opinions expressed in this article are those of the author and do not necessarily reflect the views and opinions held by dpreview.com or any affiliated companies.