Formatting memory cards?

[ginauk84]

Okay so have ordered my 20D but I keep hearing this term 'formatting the card.' I had a new camcorder last week and that also has the option to format the card. What does formatting do? Something I haven't come across as my Fuji doesn't have the option?

[robertwgross]

Part of it is exactly like formatting a floppy disk. Formatting sets up a file allocation table (FAT) which is like an idex to whatever gets stored on the card. This much can be done in the camera or in a computer. Formatting seems to wipe out all pre-existing data on the card. However, what it really does is to wipe out the index, so it just seems to wipe out the data. New files will be written and the index is updated.

The other part of formatting must be done by the camera. Once the FAT is present, it creates some folders, one named DCIM, and one named according to the image numbers that will be shot next. Then you are ready to go.

Most people just format in the camera. That works fine as long as there are no performance problems or corrupted files on the CF card.

---Bob Gross---