A few years ago, the mother of a buddy of mine was approaching her 100th birthday. She didn’t get out much anymore, but she’d been to the hairdresser and had her hair Cool Whipped to perfection in preparation for her birthday party. I photographed the festivities and got a once-in-a-lifetime shot of mother and son.
The next morning, before any cup of anything could clear the cobwebs from my head, I deleted the shots from the memory card. But I was confident I could recover the data. I’d done it with floppies, so why not with a card? I spent the next few weeks trying every trick in the book to undelete the files on the card. But they were lost. I consoled myself with the thought that I’d get that portrait again one day, but the dear matriarch never lived to see her 101st birthday.
It’s a sad story. But there’s no reason it should ever happen again. All the little gotchas that defeated me years ago have themselves been defeated by modern utilities designed for just this sort of thing.
The Secret to Unerasing
These utilities know a little secret: the data on the card isn’t really lost until it’s written over the next time you save information to its formerly protected sectors. An erase operation simply frees the file’s disk space, overwriting the file name’s first character in the card’s directory with the Greek character sigma. It’s faster than zeroing all the data and just as effective, if not as secure.
To the Rescue
One of the best utilities for recovering images is
DataRescue’s PhotoRescue 2.1. The basic version, PhotoRescue Wizard, costs $29. The $39 PhotoRescue Expert offers more measures to restore the past. PhotoRescue switches between as many as 12 data-recovery algorithms to apply a recovery strategy that’s optimized for each image. It can also create a disk image of your card, a file on your hard disk that mirrors the data on your card. This means you can duplicate the card data any number of times to try different recovery strategies and diagnostics. When PhotoRescue finds all the files hiding on your memory card, it displays a thumbnail and the file name for each recovered item.
What Can and Can’t Be Done
PhotoRescue has recovered every image I erased and every card I reformatted. But to be retrieved, the data has to reside on the card. And that isn’t always the case. Let’s look at what can and can’t be done:
If you simply erased files on your card from your camera, PhotoRescue can retrieve them by uncovering all the information that’s lingering on the memory card. You can’t see it, but it’s still there.
If you used the card to capture more images after erasing, you’ve overwritten whatever PhotoRescue might have been able to recover. Something might still be recoverable from the part of the card not yet reused.
If your camera can’t read your card, PhotoRescue might still be able to recover your images by reading the card in physical (rather than logical) mode.
Using your camera or computer to reformat your card might make recovery impossible. According to DataRescue, “Nikon and Canon digicams usually do not fully erase cards. Olympus digicams may or may not fully erase cards during a format. Sony digicams always seem to do a complete wipe.”
After an in-camera reformat of my card, PhotoRescue recovered exactly what I had recovered after merely erasing the card.
Naturally, the best approach is not to erase your card until you’ve copied your images. One copy is not enough. Two copies on different media is the minimum. You might also want to keep the copies in different locations. If something goes wrong with one scheme, the other should not suffer the same fate.
Then use your camera, not your computer, to erase the images. If you make sure never to erase files or format your card on your computer, your camera will always be able to make sense of your card. If you use your computer, your camera might not. Cameras aren’t as smart as computers.
Don’t Repeat My Mistake
Before you make a mistake like mine, get PhotoRescue or find a flash-card unerase utility you can live with. The next time you erase a card, use your utility to try to recover the images that were on it. Try it after a reformat, too. If you don’t get them all back, try another utility. Rehearsing for disaster might seem silly, but I know that my buddy and I wish I had done it. Don’t let a similar tragedy happen to you.
This article is an excerpt from
Digital Photography Hacks
, by Derrick Story (2004; reprinted by permission of O’Reilly). This hack was contributed by Mike Pasini for inclusion in
Digital Photography Hacks
PhotoRescue uses as many as 12 algorithms to recover image data.These files seemed to have disappeared permanently until PhotoRescue recovered them.