This is true for all flash media volumes. Format deletes and initializes the FAT (or FAT32) directory table. It might also do a consistency check on blocks in the volume and adjust the directory table to compensate for bad blocks, but I don't know if anyone has actually implemented doing that in a camera. It does NOT do anything to overwrite or zero the actual data bits on the volume. Format, since it re-writes the file directory tables, is useful to eliminate any possibly corrupted directory information.
Delete All individually does a delete operation on a per-file basis ... this means removing the file from the FAT directory table, one at a time, NOT overwriting or zeroing the actual data bits on the volume either. It honors "protect" attributes you might have set on files, so if you do a Delete All on a card with 200 files, 10 of which had a Protect setting, the card will have those 10 files on it after the operation is complete. This is useful now and then when you're running out of card storage but need to preserve some captures on the card. Which one is best to use depends on what you're trying to do. If the goal is simply clearing the card and you don't care about protect settings, they work about the same. Godfrey On Nov 2, 2007, at 9:29 AM, P. J. Alling wrote: > The way sd cards work it really makes no difference. Both just re- > write > the directory structure. The data will still remain. The read/write > memory of the cards has a finite number of writes. In fact erasing > the > files might even be better since the whole directory structure doesn't > have to be rewritten. > > Peter Fairweather wrote: >> I do wonder whether formatting the card each time is better than >> deleting all. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
