Picture Your Perfect Camera Page 2 of 4

Zoom in on the Features You Need and a Model You’ll Love to Use

by Derrick Story, Macworld.com

How Many Pixels Do You Need?

For many years digital photographers were consumed with the quest for megapixels. My 1.3-megapixel camera was the greatest thing in the world until the 2-megapixel models arrived. Now consumer cameras offer as many as 8 megapixels. But why are megapixels so important? You certainly don’t want to plop down those extra dollars (and use up valuable hard-drive space) just for bragging rights.

Megapixels are important for two reasons. First, they determine what size your prints can be. Second, they determine how much of the image you can crop away and still produce a good print.

Making Prints

A megapixel is a unit of measurement that describes how much information the camera’s image sensor can record. A 3-megapixel camera, for example, can record around three million pixels worth of data. Alone, each pixel is just a tiny dot of color. Together, they create an entire image.

The quality of a photographic print is determined by how closely these pixels are packed together. If there are too few pixels per inch (ppi), photos look blocky and unattractive. To achieve the smooth gradation of tones we’ve come to expect from photographic prints, photos must be printed with at least 150 ppi. For a superior print, you must keep squishing all the way to 300 ppi.

Of course, as you pack pixels closer together, your image becomes much smaller. For example, a 3.2-megapixel photo shrinks to a mere 5 by 7 inches when you condense the resolution to 300 ppi. To print a high-quality 8-by-10-inch photo, you need at least 6.3 megapixels.

So to decide how many megapixels you need, you should first consider what you plan on doing with your images. Compact cameras are great for printing 4-by-6-inch and 5-by-7-inch prints. But if you want to go bigger, you should consider investing in an advanced amateur or pro camera. I recommend at least 4 megapixels for casual shooters and a minimum of 6 megapixels for advanced amateurs.

Room to Zoom

There is an advantage to having slightly more megapixels than you think you may need—doing so can compensate for a weak zoom by giving you room to crop. Say you use a 5-megapixel camera to take a picture of your daughter playing soccer. Although you’ve extended your camera’s zoom to its fullest potential, she still seems far away in the photo.

Well, if you have a few megapixels to spare, you can actually “zoom in” even closer by cropping out unnecessary parts of the photo. A 5-megapixel camera can produce a high-quality 6-by-9-inch print at full frame. This means that you can crop out more than a third of the picture and still end up with a top-notch 5-by-7-inch print.

File Size

But before you go out and buy a 6-megapixel camera, take an honest look at your Mac setup. A 3.2-megapixel camera set at very high quality (the setting is typically called Super Fine) produces 1.5MB files. The images from a 6.3-megapixel camera at the same setting are larger than 3MB. Uploading hundreds, if not thousands, of these images could bring an aging or already strapped computer to its knees. You can give yourself more room by adding an external FireWire hard drive. But if your Mac is more than three years old, buying a new 6-megapixel camera may mean that you have to upgrade your computer, too—it’s something to keep in mind.

With a few megapixels to spare, you can crop wide shots…… for better compositions while preserving print quality.