"I have to upgrade my camera, because the latest model has more megapixels."
Really?
Do you honestly think that more megapixels mean better pictures? Actually, in some cases (most) more megapixels means softer images.
Let's say you have a standard 8.5x11 piece of paper. Now, draw 6 million dots on that piece of paper. Let's take the same piece of paper and draw 8 million dots, 10 million dots, 12 million dots, and so on. What happens as you add more dots? They get smaller and closer together in order for them all to fit on the paper. This is the same concept with digital camera sensors. The more megapixels you add, the smaller and closer together they get.
Smaller pixels = Digital Noise
Digital Noise = Grainy Photo's
Close Pixels = Softer images
Let's talk about how pixels that are close together create softer images. Let's imagine that each of the dots on the piece of paper are actually small cups. When the image is passed through the lens and ends up on the sensor it is presented as colors of Red/Green and Blue. Each "cup" fills up with the color, if the "cups" are really close together and there is any shift in the camera (shake) the "cups" will get the colors of the next "cup". When the "cups" are further apart, there is less chance of the colors filling up the next "cup"
Whew....thats alot to say....
Let me break it down. As I moved from 6 to 10 to 12 megapixels I had to shift on how I photographed to account for the greater amount of pixels.
For the majority of people out there, 6-8 megapixels is more than enough. Let's face the truth...how often are your pictures used for anything other than web images, email or prints that are no bigger than 8x10.
So, if you want to upgrade a camera don't do it just because you think you need more megapixels. Do it because you want to achieve higher ISO's or more frame per second or 14bit color depth.
Hope this helps to clear up some of the myths out there about megapixels.