NYT:
It goes like this: “The more megapixels a camera has, the better the pictures.”
It’s a big fat lie. The camera companies and camera stores all know it, but they continue to exploit our misunderstanding. Advertisements declare a camera’s megapixel rating as though it’s a letter grade, implying that a 7-megapixel model is necessarily better than a 5-megapixel model.
A megapixel is one million tiny colored dots in a photo. It seems logical that more megapixels would mean a sharper photo. In truth, though, it could just mean a terrible photo made of more dots. A camera’s lens, circuitry and sensor — not to mention your mastery of lighting, composition and the camera’s controls — are far more important factors.
Here.