> > Frank, > > I just had a hard drive accident while on a boat trip on Lake > Michigan . . . long story short, an entire days worth of shots > (approximately 230) were lost from the hard drive, and I had already > formated the 2 cards I had used to take these shots. I shot some > pictures onto each of these cards before discovering the loss. After > worrying for a few days, I finally arrived home, downloaded one of the > pieces of software that lets you 'undelete' and found about 75% of my > pictures remained on the cards (because I stopped shooting on them as > soon as I discovered the loss). > > My summary: I believe that the card just clears the FAT and resets > the two directories that it needs.
This is they way most computer devices "delete" or "format" things--they just mark the space as unused, without actually removing anything except the metadata that describes what was stored where. That is why to safely delete credit card information or that sort of thing you need a program that deliberately overwrites garbage on top of the data you wish to destroy. I have had twice to use recovery software to reclaim pictures shot with a Nikon D1H (due to a piece of, IMHO, utter stupidity in MacOS' handling of hot-swappable devices--not any fault of the camera) and found that usually something over 90% are recoverable providing that new pictures have not been written over them. Flash cards apparently have some sort of load balancing at some firmware or software level which probably helps new pictures not overwrite old pictures until they have to. Data on hard drive is usually salvageable, but rarely is it worth the cost to undertake professional data recovery. DJE
