Verify the integrity of a flash/SD card on a Mac

Last minute camera shopping

The week before going on a holiday, I realised my old Canon Ixus 40 camera would no longer live up to my expectations. So I quickly checked dpreview.com for the latest and greatest compact camera’s and decided I wanted the Canon PowerShot SX240 HS. 15 Minutes later I found myself in the Media Markt with the camera in my hand (unfortunately only the silver colour was available, I had hoped to buy the black one).

I need a bigger memory card

I then realised that my existing 512MB and 1GB SD cards would no longer be large enough for the 12Mpixel photos of this new camera. A few meters down the corridor was a huge wall covered in memory cards. I decided to buy a Samsung 8GB SDHC card, which would be able to hold up to 1500 photos or an hour of HD video. When I returned home, I formatted the card in-camera, and played around with the photo and video functions. Three days later my holiday would start and I would have a good (enough) camera to capture some fine moments!

Corrupted photos

Fast-forward about two weeks, half-way into my holiday. I’ve happily been taking photos and videos with my new camera. While I’m reviewing the last five photos, the camera suddenly displays a “broken picture” image on the screen. I take another photo, review it and it’s immediately “broken” again. I’m approximately on two-thirds of the card’s capacity and it is corrupting my photos. I do what I’ve learned from experience with corrupt memory cards: turn off the camera immediately, remove the SD card, and to be sure, “lock” the card (making it read-only) using the physical switch on the SD card. At this point, I just hope for the best that only those last two photos were corrupted.

Back at home a week-and-a-half later, it turns out I’m extremely lucky! Indeed only those last two pictures were corrupted! Continue reading Verify the integrity of a flash/SD card on a Mac