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Unerasing Lost Images

By Mike Pasini, Editor
Imaging Resource Newsletter

"If this is your first time (oh, there will be others), start by deliberately making the same mistake again."

It happens. "My name is [unintelligible]. I erased my media card before I copied the images."

Hi, [unintelligible]. We all make mistakes. Before you panic and do something (else) foolish, work on a good excuse. Here's a starter kit:

  1. "I thought you copied them." ("You" could be anything from an African violet to a goldfish, a cat, a spouse, or a long lost relative already framed on the mantel.)

  2. "I pressed the wrong button." Nobody has to know that no buttons are involved.

  3. "It said 'Copy.'" Well, desperate measures call for desperate acts.

OK, now panic. Get it out of your system.

If this is your first time (oh, there will be others), start by deliberately making the same mistake again -- but to a second card or floppy. You can try all sorts of recovery techniques on the second one until you find something that works.

The first thing to realize is that, whether you are using a Macintosh or a Windows PC, your storage device is (no doubt) formatted for MS-DOS.

Macintosh computers have no trouble reading and writing MS-DOS media (and, just for the record, PCs can handle Macintosh media with third-party software). But neither of them is any good at running disk utilities on the other's media. Your Norton knows your native file system, period. So recovery of a DOS-formatted card is a Windows task.

Unfortunately, Windows may see your card only as a network drive (where, as with floppies, deletions are not safely buffered in the Recycle Bin). And it's rude to reorganize the directories of network drives, so your usual unerase utility may not work.


But there's hope. No guarantees, but hope. (Precious little hope if you've already stored newer images on the card. Or just reformatted it. But you didn't do that. Right?)

"To actually erase a file, you have to write over every byte. And more than once, if you believe certain U.S. government specs."

So to unerase from your DOS-formatted card, you'll need access to a Windows computer with a card reader and software that will recognize your card and unerase your files.

There are a number of unerase utilities that may help. We know of one 64MB CompactFlash card saved by the shareware program Recover98, even after a few new shots were written to it by a Nikon 950. We've had no success with MS-DOS Undelete, Norton Quick Unerase (which has trouble with files as large as image files), or shareware like Directory Snoop -- either because they wouldn't touch a network drive or they couldn't find the first cluster of deleted files. The freeware program Emergency Undelete for Windows NT sounds promising, but we haven't personally been saved by it. (If you have a success story with any unerase utility, let us know about it at [email protected] and we'll pass the information along.)

You see, these utilities know a little secret that you may not -- the data on the card is not really erased. It isn't lost until it's been written over with new information saved to its formerly protected sectors. Instead, 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, so it no longer appears in the active file directory. It's faster and just as effective. If not secure. To actually erase a file, you have to write over every byte. And more than once, if you believe certain U.S. government specs. (That's what the Norton Wipe command is all about.)

If you're lucky, your unerase utility will just ask you for the first letter of each erased file name it found. And a few keystrokes later, you'll have your file right back where you hoped it still was.

Long ago, we made the stunning revelation that everyone (except goldfish) makes mistakes. It's our intelligence misfiring. So take heart! But if you're really intelligent, swing the odds in your favor. Adopt foolproof habits -- like deleting images only in your camera, using your computer solely to copy, and relying on your camera to subsequently delete. While looking at your images on your computer monitor. From the CD you just burned.

You can never be too safe when it comes to deleting files.

This article is reprinted from The Imaging Resource Digital Photography Newsletter,
Beginner's Flash Column, published September 22, 2000