Archive | November 25, 2012

A bump in the road

A partially corrupt RAW file. This type of damage is often the result of a physical flaw of the hard drive, and cannot be repaired.

I have been photographing earwigs recently, and this reminded me of another group of hexapods, the members of which often have big, pincer-like cerci, the diplurans. “I’ll write a post about them”, I thought, “now, let’s see what kind of pictures I have.” I started looking and located a bunch of shots of diplurans that I took in 2006 in Ghana, but when I tried to open the files I received a Photoshop error telling me that the files were in an unrecognizable format. This usually means that the file is corrupt. Other files opened, but were partially garbled.

“No problem, I’ll just get the backup files.” Same error. Second backup, same error, third backup, same error. I began to worry. I am pretty good about keeping all my files backed-up, on multiple, physically separated drives, but the system has clearly failed me.

My normal file-saving procedure while in the field is as follows:
1. Copy files from CF/SD cards to the hard drive on my laptop
2. Catalog image files in iViewPro, rename them, discard crappy shots
3. Add keywords and captions to the files
4. Copy the annotated files to two separate, portable hard drives
5. Back home, copy the files from the laptop to a separate, stationary hard drive (HD1)
6. Copy the content of this drive to two additional, separate drives (HD2 & HD3), occasionally I add a fourth drive (HD4) to the lineup.

After this is done I feel that the files are safe, and I reuse the portable hard drives for another project. Until a few years ago I would have also burned DVDs with an extra copy of the files, but as the files got bigger, and more numerous, I abandoned the practice, opting instead for adding another hard drive to the backup.

All my backup files had the same type of corruption, which must have originated on the first drive, and was copied to other drives.

What must have happened in the case of my corrupt dipluran shots was either a copying error during the process of transferring files from the laptop to HD1 drive, or file corruption on the HD1 following the transfer. Regardless, the damaged files were then duplicated to drives HD2-HD4. So, it seems, all is lost.

Luckily, not. Back in 2006 I still burned DVDs with file backups, using the original files from the laptop as the source. I pulled them out, and sure enough, uncorrupted, original files were there. Alas, going back to using DVDs as a backup is simply not an option. During my recent trip I shot 352GB of images, which translates to 42 DVDs (DVD+R, 8.5GB each), or about 14 hours of burning and swapping DVDs (assuming 20 minutes per disk.) What are my options then?

For one, I will be copying my files from the camera’s card simultaneously to at least two separate drives. You can do it directly in the Finder (or Explorer), or use a dedicated program, such as Photo Mechanic (this program also allows for renaming files while copying them.) Second, I will no longer reuse the portable drives that hold the files copied from the cards in the field. These drives are becoming so cheap that they are now a very sensible alternative to large, external, independently powered hard drives (I may even consider keeping the CF/SD cards with the original shots and not reusing them; some photographers already do it.) And third, I will add storage space to my Dropbox account. There is no way I can keep all my photos there, but at least I can safely store the most important shots. The experience of losing some of my original files was a reminder that no single backup method is 100% safe, but hopefully a combination of several methods will reduce the chances of a disaster similar to what I saw today.

As for the diplurans, I think I will need to write another post about them later on. These are very cool animals, close relatives of insects, and they deserve a proper writeup. They have an interesting reproductive behavior and a sophisticated maternal care, and give us a glimpse of what the early chapters of the insect evolution might have looked like.

Dipluran (Japyx sp.) from Ghana. I was lucky to have an extra, uncorrupted copy of the original Canon RAW file on a data DVD made immediately after taking the photos.