Memory card capacity doubles and prices drop by half with amazing regularity. Any time digital photographers start to make the transition from one common size to the next-larger size, doomsayers come out of the woodwork warning against putting all your photo eggs in one basket. The same folks who are saying it’s foolish to use a single 8GB memory card, rather than two 4GB cards (or even four 2GB cards), were panicking over the thought of storing their images on one of those new-fangled 1GB memory cards, rather than the 256MB versions common only a few years ago.
The fact is, unless you’re using a camera that accepts more than one memory card at the same time and you write each picture to both cards, you’re always storing your pictures in a single basket until you choose to back it up. The chief variables are how many pictures you’re putting at risk and the nature of the peril. If you use more memory cards, you increase your chances of accidentally formatting one or damaging another.
With CompactFlash cards, it’s actually more common to damage the camera through over-frequent insertions and removals than to lose images to a faulty card. Nor do memory cards work perfectly until they’re full, and then mysteriously fail. It’s just as likely that a 4GB card becomes corrupt after, say, 2GB of photos as it is for an 8GB card to flake out after 2GB of images have been stored.
Your risk is identical in either case. Would you insist that your family drive in two cars to each destination? How many people are riding in each car? How likely is a traffic accident in your location? Obviously, the risks are impossible to assess. Each photographer should realize that malfunctioning memory cards are also exceedingly rare, and each must decide for him- or herself how many images he or she can comfortably expose to such a minuscule risk.
In my day-to-day shooting, I use the largest memory cards I have (at present, 32GB cards) to avoid needless swaps (which would cause me to lose pictures that I couldn’t take during the switch-over). When I travel or shoot any kind of once-in-a-lifetime event (such as a wedding), I back up my photos on the spot — to two backup devices. I don’t care how many baskets I must use,