Nothing impedes the joy of digital photography more then defective memory cards. Today, while trying to make a small movie while skidding down a nicely snow covered hill in a park, the dreaded Memory Card Error blinked on the display.

Of course, I tell everyone who asks that you should write new memory cards full with data multiple times before you can trust them. The reason is that the Flash memory used in these cards has usually defect areas. To compensate that, there is more memory hidden on the card then what is written on the label. When a memory block shows signs of defects, the on-board error correction of the memory card internally uses a block of the excess memory instead of the defective block. Writing the card full with nonsense data multiple times makes sure that the usual early defects are recognized and mapped out, before you put any important stuff like your pictures on it. You can think of it as a sort of “burn in”, like a new car that needs a certain milage before the motor is considered to be fully performing.

Naturally, I had not done this “burn-in” with the card in question. Now it did not wanted to be read either through the camera nor through an SD-card reader. After a bit of experimenting, I succeeded in recovering most of the images and movies with the following procedure:

First, I used the camera-internal format option multiple times, until the camera no longer complained about the card error. This was needed to get the card into a state where the computer would recognize it again as a readable memory card. “Formating” on nearly all cameras does not really erase the pictures, but merely deletes the references to them in the file system. Then I used the trial version of PhotoRescue to determine if there is data worth paying for left on the card. PhotoRescue is made by Datarescue, the company that also makes IDA Pro , the worlds premier tool for disassembling and software reverse engineering.

To my great joy, PhotoRescue found all the images and most of the movies, except the one that got written onto the bad memory block that triggered the problem in the beginning. Fair enough. The trial version lets you see everything that can be recovered. So happily spent the 29€ for the tool that saved my day and recovered all the images and most of the movies.