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.

Megapixels are slow. Higher pixel counts means more data flying around in your camera's electronics. It takes longer to move more data than it does to move less. In general, cameras with higher pixel counts are slower to start, and they write files to disk more slowly than similarly priced cameras with lower pixel counts. All those pixels won't matter if you miss the perfect shot altogether because you're waiting for your camera.