Since the beginning of the digital era, camera manufactures have been in a race for the highest megapixel count. Megapixels are frequently listed at the top of the list of specifications for a camera. Even the sales associates at a brick and mortar store are trained to use those megapixel numbers in their sales pitch. But have you ever wondered how many mega pixels are enough?
The answer to this question depends upon what you are trying to accomplish. For snapshots and informal portraits, we frequently reduce the size of each photograph to about 6 MP (3072x2048). Most clients don't want or need a larger file, and these will print beautifully as large as about 8x10. Since people rarely print portraits larger than that, the size is more than enough for their needs.
The situation is very different in the fine arts market. Many photographers believe that they need a fancy camera because a high megapixel count is absolutely essential. Many artists will argue that there is a significant difference between a 15 MP and a 21 MP camera....but exactly how much difference is there?
Take a look at the figure above. If you make a fine art print at 300 DPI, the difference between the 15 MP and 21 MP prints is less than 3 inches in the longest dimension. While it is true that more megapixels will buy you some extra details, the difference in the size of the prints is quite small.
So, the next time you buy a new camera, ask yourself what you intend to use the camera for. Think about all the features on the camera. The megapixel count is just one feature. What else is important to you?