All that aside, more megapixels, as most photographers know, doesn’t actually mean an image with higher resolution. While resolution has come to be accepted generally as a term for the active pixel count on a sensor, too many photodiodes actually can be a bad thing when squashed onto a sensor just to boost a megapixel count for promotional purposes. Smaller light-sensitive areas can mean photodiodes that collect less information, as well as increased gaps in between the photodiodes for increased loss of light.
Myth: The larger the print, the bigger the sensor resolution needed
Secondly more megapixels doesn’t always equal a bigger and better print. It’s possible to achieve a better image through know-how, and a good, clean image, even one taken at a smaller resolution, always trumps a low-quality image taken at a higher resolution.
This isn’t to say that a 6-megapixel point-and-shoot will provide you with better or even the same results as a pro level D-SLR. There’s an acceptable maximum to every file size. (The graph provides a good estimation of file size capabilities.)