CNET editors' digital camera buying guide:
How many megapixels do I need in my digital camera?
What you need to know, from the kind of user you are to current technologies.
How many megapixels do I need?
As much as we'd like to give a one-word answer, this is one of the trickiest questions in digital photography, so we'll provide a short answer and a long answer.
The short answerFor any images you plan to print or retouch, we recommend you stick to 7-megapixel resolution and higher; Web- and e-mail-only photos should be fine at resolutions below that.
The long answerIt depends upon what you're doing with the picture and how you're doing it.
Hint: If you're going to display or print pictures at smaller-than-actual-pixel size, resolution doesn't matter much--opt for the camera with the best color.
The images below were shot with a 4-megapixel and a 6-megapixel camera, respectively, and scaled down to smaller-than-actual size. Aside from slight color differences, they should look pretty similar.
Let's say you want to blow up a detail shot or print a picture; that's where extra resolution comes in handy, for both printing and Web display. The 4-megapixel shot (left) is a bit blurry, but the 5-megapixel (middle) and 6-megapixel (right) shots come pretty close to each other. Which could you live with?
Now, suppose you want to crop in tightly on that "20." That's where higher resolution comes in handy. Once again, here are the 5- and 6-megapixel shots, cropped so that the "20" fills the same size space, plus a 10-megapixel version.
The 5-megapixel shot (left) loses some cohesion, but the 6-megapixel (middle) and 10-megapixel (right) shots are pretty comparable to one another. The key is knowing how close you're going to want to get.
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