Hands On: When Flash goes crash

Every so often the Hands On mailbox receives a desperate request from a reader who has just lost all their holiday, wedding or other once-in-a-lifetime event photos and is hoping against hope that there may be some way of retrieving them.

If you find yourself in this situation right now, you’re in luck (if you can call it that), because this month’s column is all about retrieving images from reformatted, damaged and corrupt memory cards.

If all your photos are safe and sound and backed up in three different locations, give yourself a smug pat on the back and put this issue somewhere safe: you never know when it’s going to happen to you.

Prevention, as the well-worn phrase has it, is better than cure, and there are a few things you can do to ensure that catastrophe is less likely to erase your precious memories before you get them off your media cards.

The first thing to do is to copy the images onto your hard drive and back them up at the earliest opportunity. I’m always astonished when friends show me photos on their digital cameras that go back months. Larger 4GB and 8GB cards are useful if you shoot a lot of images, but using them as an excuse to put off transferring files to your PC is asking for trouble.

Use a card reader to transfer your files to your PC rather than attaching the camera itself, particularly if you’re experiencing problems with the card. And once you’ve safely transferred and backed up your photos, format the card in the camera before using it again.

What can go wrong?
Judging by the Hands On mailbox, forum posts and the testimonials on recovery software and services websites, the most common reason for losing digital images is accidental erasure or formatting.

Sometimes your camera can be responsible without any intervention on your part. Batteries may fail during a write operation (after you press the shutter but before the images have finished writing to the card, for example). And occasionally weird stuff happens for no apparent reason, such as your camera suddenly informing you that there are no images on a card when you’ve just spent the last half hour shooting.

If you take the advice offered earlier, then if you do accidentally format a card full of images you’ll only have lost your most recent photo session. Compact Flash and SD cards use the Windows Fat (File Allocation Table) format. Cards up to 4GB use Fat16 and larger cards use Fat32. As with a hard disk, when you erase files, or quick-format a drive, the data itself isn’t usually erased, only the directory is amended, with pointers to the image data removed and the memory locations occupied by the files shown as available for writing.

The first rule when things go wrong is to stop using the card immediately and remove it from the camera. There’s a good chance that the image files are still on the card, intact, and that you’ll be able to recover them using inexpensive file recovery software.

On test
I’ve carried out limited testing using five inexpensive data recovery applications. The most costly (assuming sterling hasn’t yet reached parity with the dollar) is £28.15 and most are available as trial downloads. In many cases the trial will tell you whether the program can find recoverable files on the card, and you can pay for the full version of the software to recover them.

For each of the applications I attempted to recover photos written to three cards using two different cameras. The cameras were a Canon Eos 20D SLR and a Nikon Coolpix S200 compact. The Eos 20D was used to write 200 images to a 2GB Sandisk Ultra II CF card, and an 8GB Lexar Professional 133x CF card. The Coolpix was used to record 100 images on a Sandisk 1GB SD card.

Because of the proprietary nature of camera Raw files, it can be more difficult for recovery software to identify and rescue Rawfiles than JPEGs or other published image file formats. Of the files shot with the 20D to the two Compact Flash cards, 100 were Raw .cr2 files and 100 were JPEGs. All those shot on the Coolpix were JPEGs.