In most cases, SLR photographers like to aim their shots through the viewfinder. Those using less expensive cameras tend to aim their photos through the LCD screen, which for non-SLR cameras is more accurate.

Image storage
When you take a picture with a digital camera, the pictures you've taken are saved on a storage card, a form of non-volatile computer memory. In most cases, it'd be impractical for you to shoot a picture and have it recorded directly by a computer. Instead, you're going to need to store your pictures in an intermediate storage location, somewhere you can keep your pictures until you're ready to send them to your computer. In most digital cameras, this intermediate storage location are flash cards, which you can see in Figure F.

FIGURE F


On the left is an Secure Digital flash card, on the right is a Compact Flash card. Roll over picture for a larger image.

A great article on flash cards and digital storage is "Megapixels and digital storage media," at http://www.connectedphotographer.com/issues/issue200311/00001142001.html.

For those of you who are old-school film camera users, the flash card is somewhat analogous to film. Of course, with film, you use the film once and develop it. More pictures mean buying and developing more film. With digital storage cards, you can reuse the cards over and over, leading to one of the biggest cost-savings in digital camera purchases.

Batteries
Another important element of a digital camera is the battery, the component that powers the whole system. In early digital cameras, battery life was horrible. You might get 20 or 30 minutes of shooting before the battery died. Today, battery life is much better. You can generally get a day's worth of light shooting out of a typical camera battery.

Batteries come in all shapes and sizes, like those shown in Figure G.

FIGURE G


On the left is the battery for my digital SLR, on the right is the battery for Denise's smaller Casio camera. Roll over picture for a larger image.

Most mid-level and above digital cameras use some form of removable, rechargeable battery, while cameras at the very low end sometimes use off-the-shelf AA or AAA cells, and other lowest-end cameras have non-removable batteries. Never buy a camera that has a non-removable battery.

In my camera collection, I have an ancient digital camera (it's probably seven years old). The battery can't be removed or replaced and now will no longer hold a charge. For a while, I'd just plug it into the wall to use, and as a result, I was only able to use it only around the house, in places where I could get a power cord to reach. To be honest, I have no idea why I don't just toss the thing!

Buttons and controls
Let's move from the inside of the camera body back into the outside, physical world and talk about buttons and controls. I mentioned them early when I talked about my big ol' hands.

In addition to the lens, LCD, and viewfinder, you need some way to tell the camera when and how to take a picture. You may need to adjust the settings, you may need to adjust the amount of light going to the lens, zoom in or out, and so forth. All your interaction with the camera's components is done through the buttons and controls on the camera, like those shown in Figure H.