There was a time when I'd explain the basics of digital photography by describing the memory card as "digital film." These days, digital cameras have been around so long that some people have never used a film camera, so my comparison is getting a little dated. Nonetheless, flash memory cards play a critical role in photography, holding your digital photos until you can get them onto your PC for more permanent storage.
Whether you're just getting started in digital photography or have had your camera for years, this week I've got some important tips for how to handle your camera's memory card.
1. Don't Delete Photos With the Camera
This runs counter to conventional wisdom, but as a general rule, I think it's a bad idea to prune unwanted photos from your memory card using the camera's Delete button.
First, there's the power management angle: It takes precious battery life to review and delete photos from your camera. And when you get right down to it, would you rather delete a few bad photos or have enough juice to shoot some more pictures?
Second, there's the fact that it's really hard to assess your photos on the camera. The LCD is so small--and the overall brightness and colors so inaccurate--that you're better off discarding unwanted photos on the PC, when you have the benefit of seeing everything on your monitor.
Third, there's the risk of accidentally deleting a photo you want when handling the awkward controls of your camera. You might not notice you just deleted a great photo of Elvis disembarking from a UFO, and that would be a shame. And if you make a mistake during the delete process, it's easier to "undelete" a photo on the PC--just retrieve it from the Recycle Bin. To recover a deleted photo from a memory card, you need to use a photo recovery program.
So, the bottom line: I highly recommend that you transfer all our photos from your camera to your PC first, then assess and delete unwanted photos from your computer's hard drive.
2. Format Your Card Regularly
Once you have copied your photos from your memory card to your computer--and they're safely on your PC, where they will presumably be backed up (you do conduct regular backups, right?) you can clean up your memory card.
There are a lot of ways to do this. You can open the memory card in Windows, select all the files and folders, and press the Delete key. This is fast and easy, and I do it frequently, especially if I've already got the memory card inserted in my PC and just finished downloading the photos. Another option is to return the memory card to your camera and press the button or menu option to delete all your photos. This is fine as well--it's essentially the same as deleting the photos using Windows. The advantage to this approach is that if you have "protected" any photos (generally using the button with the key symbol on your camera), they will remain safely on the memory card.
Finally, you can format the card. One word of warning: Don't format the card using Windows, since your camera might not be able to read a Windows-formatted memory card. But your camera has a formatting command built in, and it takes only a few seconds to format a memory card. If you have any "protected" photos you're trying to preserve on your memory card, though, since this will nuke the entire card.
Formatting the card clears out digital debris that builds up on your card, which improves performance. Some people format their memory card after each and every photo session. You can do that--there's no harm in it--but if you delete your photos using your camera's Delete button rather than its Format command, it's a good idea to format your card occasionally, such as after every five or six times you download and delete your photos.
3. Have a Spare
It's a good idea to have more than one memory card. These days, memory is pretty cheap, so you can carry a second or third card in your card bag "just in case." Just in case what?
For starters, you'll want a spare in case you fill up your card and need to take some more pictures because you stumbled across Bigfoot having a banjo competition with the ghost of Les Paul. A second card eliminates the need to selectively delete photos on the fly (that's tip #1) or reduce the photo size or quality to cram more on.
A spare card can also come to the rescue on those rare occasions when your memory card fails. Yes, it can happen.
4. Know Your Card's Life Expectancy
Memory cards are one of our most wonderful modern inventions, because they store a massive amount of information with no moving parts. That means you can drop them, sit on them, even accidentally run them through the washing machine and most of the time they'll keep on ticking.
Nonetheless, they're not indestructible, and they have a limited lifespan. Memory cards can be written to a set number of times only, so your cards will eventually stop working. Since you can't easily track the number of times you're written data to your memory cards, a more practical alternative is to expect your card to work for about 8-10 years. I write the month and year that each of my memory cards enter service using a black marker directly on the front of the card. As the cards approach their expiration date, I recycle and replace them. Sure, they still have some life in them, but they're cheap enough that I'd rather buy a new card than lose a slew of photos because I waited too long and used the card right to its failure point.