Reply #3 - December 23, 2009, 06:42:50 AM
<puts geek hat on>
A hard drive, or flash disc in this case, stores all of the data in little blocks called sectors which are all the same size. When you save a file that's smaller than a sector, typically 16 or 32k, it gets put into a sector and we move on. Larger files get split between sectors. So a multmeg image file may be in dozens or hundreds of sectors across the disc. Also on the drive is an allocation table. When a file is written the allocation table is updated so the computer can find the file later. Without that table it would be just sporadic data. When you delete a file it is removed from the allocation table, but the data is still on the drive. But since the table doesn't know it's there the drive thinks those sectors are now available and will write over them with new data when the need comes up. Same thing with a quick format except it erases everything from the table.
Data recovery software goes through and looks at the sectors and tries to figure out what the data is. Sometimes it's able to put the pieces back together.
</geek hat off>
Do any of the programs give you a list of what can be recovered? It's nice that one could pull a single file, but if we're talking about hundreds of images then one probably wouldn't help you much.
What brand is the card? I think Sandisk offers, or used to, a program on their site for recovery that worked on their cards. Other companies might do the same.
And the important thing is to not do anything else with the card until you've gotten what you need off of it. Shooting another picture with it could write over what's there.
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