With summer and all that it holds fast approaching, it’s time to start thinking about capturing your memories. Digital cameras began outselling film cameras in the last year or so. With all the hype associated with digitals, it’s hard to know just what to look for.

Megapixels are the rating used by camera manufacturers to rate the relative quality of a camera. Megapixels are determined by the number pixels (how computers create images) in millions a camera is capable of capturing at its highest image quality. Think of it this way. If you use your monitor at 800 by 600 pixels (the standard these days), it displays 480,000 pixels or ½ megapixels. Conversely, a 1 megapixel image is roughly 1200 x 800 pixels. A 4 megapixel image is roughly 2400 x 1800 pixels.

The resolution of a camera affects three measures of size: image size (the pixel dimensions on the screen like in the example above), file size (amount of memory or hard drive space used) and print size (how big it looks when printed). The megapixel rating you choose will depend on how you plan to use your pictures. If you’re taking the typical family vacation shots that you want to print out as 4 by 5 inch prints, a 3 megapixel camera is a good choice. If you primarily use electronic versions of your pictures and you’re only printing occasionally, you can buy a little less camera though I’d recommend you still stay above 2 megapixels. If you need to print larger, cleaner images then choose more megapixels. As a rule of thumb, 7 megapixels print well at 8 x 10 inches. It’s a safe bet that you’ll pay about $100 for each megapixel you choose (i.e., a 3 megapixel camera is roughly $300).

Most cameras have some combination of optical and digital zoom features. Optical zooms physically move the lenses to make objects appear closer. Digital zoom creates an approximation of an optical zoom using the camera’s electronics. Optical zooms provide a clear, natural view of your subject, while digital zoom images can seem a little blotchy. Find a camera with the maximum optical zoom. In fact, if it were up to me, I’d ditch digital zooms altogether.

Digital cameras can eat regular batteries. Battery manufacturers produce lithium batteries geared toward electronics like cameras. Look for a camera that allows you to use either lithium battery “packs” as well simple AA cells. Lithium batteries will give you days, weeks, even months of shooting. The ability to also drop in AAs means that you’ll always be able to find batteries in emergencies, like running out of juice at your Aunt Lois’ house.

I’ve heard too many negative things about so-called “docking stations” for cameras. These are supposed to make it easy to transfer or print photos. They don’t. You might, however, pick up an AC adapter for you camera. This can save your batteries when you move your pictures from your camera to your computer.

The “film” of a digital camera is its memory or storage. Cameras use memory cards of various types for storing pictures before transferring them. The more storage on a memory card, the more pictures you can store. When you first buy your camera, make sure that it either includes a memory card or that you buy one. Buy the most memory that your wallet will let you. You might even want to pick up a spare, just in case.

Keep in mind that you can fit more pictures on both your memory card and your hard drive by adjusting your camera’s resolution down. My little 2 megapixel Kodak with a 64 megabyte card (not a big card) will hold about 80 pictures at the highest resolution, 150 at the middle and almost 300 pictures at the lowest setting. We tend to keep ours at the middle setting.