The myth of maximum megapixels

Computerworld - Camera vendors and consumer electronics retailers sell digital cameras as if the pixel count -- the number of pixels a camera's electronics can capture -- is the most important measure of quality. I'm here to tell you that pixel count has become unimportant almost to the point of irrelevance. Megapixels don't matter anymore.

Ten years ago, consumer-level digital cameras weren't capable of taking good pictures. The optics were lousy, the electronics were unsophisticated, and the settings were relatively limited. Buying a better camera back then meant spending big bucks for a 2-megapixel model rather than, say, a 1.3-megapixel one.

As overall digital camera quality rose, so did pixel counts. Then, a couple of years ago, the industry silently passed an invisible milestone: Affordable consumer cameras reached, then exceeded, the number of pixels nonprofessional photographers could practically use. The current standard is just over 10 megapixels.

In an effort to convince you that your camera is obsolete and you need to buy a new one, camera vendors keep harping on the more-megapixels-are-better myth.

Their message isn't completely false. In fact, older cameras are obsolete, and if you own one, you do need a new one -- but not necessarily one with maximum megapixels.

The reality is that all areas of digital camera technology were improving at about the same rate as pixel counts were increasing. Most of these advancements have resulted in better photos for amateurs; picture quality is way up, and so are pixel counts. Vendors will tell you that these two facts are linked. But what they don't tell you is that the improvement in picture quality is the result of improvements in just about every aspect of a digital camera except pixel counts.

The reality is that these other factors, which make or break digital camera image quality, are complex. Most buyers aren't willing to put in the time it takes to understand those factors, so everyone clings to a simple metric -- pixel count -- that appears to correlate with quality.

Each amateur photographer has a pixel count "sweet spot" that best suits his photography style and abilities. For most people, that's somewhere in the 4-to-6-megapixel range. Above that, however, increasing the number of pixels generally reduces the quality of pictures.

That's right. I said it. More megapixels are bad. Here's why:

Megapixels are expensive. Assuming you have a set budget for buying a new camera, the quality of pictures generally will be better if you spend less on pixel count and more on image sensor quality, lens quality, better electronics and faster performance. I'll discuss these factors a bit later.