The Canon EOS Digital Rebel XSi/450D Companion

CHAPTER 4

MEDIA CARDS

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Media Cards

Film is an amazing invention because it’s a single material that can both capture

an image and store it. With a digital camera, the image sensor does the capture,

but it doesn’t have any capability to store an image. For that, a digital camera em-

ploys a memory card of some kind. As you’ve already learned, the XSi uses Secure

Digital cards (or SDHC cards, a faster, higher-capacity version of SD).

Flash memory cards are similar to the RAM that’s in your computer but with one

important difference: ey don’t require power to remember what’s stored on

them. So, after you turn the camera off, the images remain on the card, even if

you remove it. Consequently, it’s perfectly safe to take out a full card and replace

it with another.

Your camera treats the card just the way your computer treats your hard drive.

e camera creates folders on the card and stores files in those folders, each with

a different name.

Because cards are so small and because they can pack huge capacities, it’s pos-

sible to shoot a tremendous number of images with just one or two cards. In fact,

because the XSi’s battery is good for “only” about 500 shots, if you’re carrying a

couple of high-capacity cards, you’ll probably run out of battery before you run

out of storage.

One Big Card? Or Lots of Small Ones?

With the range of capacities available, you can carry storage in several ways