Digital data is easily corrupted, leaving pictures barely recognisable.
Illustration: Jo Gay.
A HEART-breaking email came to me the other day: ''On a recent overseas trip I lost all of my photos from my SanDisk 4GB card. I sent the card off to a camera repair shop and they were able to recover all but about three dozen of 1000 so I am very lucky. The issue that interests me is that many of the corrupted photos look fine when displayed as a thumbnail but when I open them to full screen a grey area of varying size blocks out some portion of the photo from the bottom up.''
There are many things to be said about this little tragedy. The first is that the reader could have done what the camera repair shop did and it wouldn't have cost a cent. Do a web search for ''freeware data recovery'' and you will find several free applications that restore deleted, formatted or otherwise corrupt files from memory cards or hard drives.
We use PC Inspector Free Recovery, which is geeky, or, if we are not in the mood for coping with an arcane interface, we turn to Avanquest Data Recovery Pro, which costs money. The latest version, called Fix-it Utilities, can be downloaded here for $10.
These utilities do a miraculous job of recovering lost files, but there will usually be some data damaged beyond restoration. And, Murphy being on hand at all times, the bad files will be the priceless photos you will never be able to take again. Usually there is a frustrating partial recovery - you can see what should be there but part of it is missing.
Digital data is fragile. It can easily be corrupted, erased, lost or stolen. Putting 1000 files on a 4GB card is a risky enterprise. It is a case of all your eggs in the one digital basket. With film, we didn't have much choice when it came to security on the move, but with digital we do.
If we were on a once-in-a-lifetime trip we would take a portable back-up storage device, probably a seven-inch Android tablet with a USB connector and a microSD expansion slot. The Samsung Galaxy Tab 7.7 fits the bill, and its wi-fi will connect you with the cloud. Dropbox, Microsoft SkyDrive and Apple's iCloud provide secure back-up. Adding together the memory in the tablet, the microSD card and the cloud means there is no need to perilously overload the memory card. (Check that you have a camera-to-tablet connector cable; it may be an option to be purchased.)
Android tablets are better than Apple iOS devices for this process because when you get home you can connect them to your PC and transfer the photo files without having the torment of iTunes.
Finally, the best security procedure is to unload the memory card every night so it never becomes too full.