How many Megapixels? You might not need as many pixels as you think - more does not mean better.

Digital cameras first came about in the early 1990's without even a megapixel in sight. It did not take too long for the technology to move on, and eventually the first megapixel camera was introduced into the marketplace. From then on cameras have been increasing their pixel count rapidly, and the last few years have seen a surge in growth of around 1 megapixel per year.

First of all we need to really understand what megapixels are, and why they are so important. The term pixel is a derivation of picture element and megapixel just means there are one million of them.

Pixels are very important because they determine the quality and clarity of the picture. They can make a huge difference to what you see when the picture is developed, and how that picture will look if the picture is enlarged. To put it simply, the pixels show the detail; the more the pixels, the finer the detail. However, try not to get caught up in the megapixel race, as there is one very obvious, but overlooked factor associated with ever increasing pixels, and that is the subjects of the pictures do not get more detailed, because they cannot change, and there is only so much detail that can be captured. A higher pixel-count really comes into its own when the picture is being enlarged.  This helps to retain each detail that the eye can see without the aid of a magnifying glass. What you really need to think about is what you want to do with the picture. If you want to create a good quality 6x4 image to develop on your home printer, then 1-2 megapixels would give you a picture of good quality that you could show with confidence, and should you wish to increase the size of the picture, only then would you need to consider more pixels...

A 1-2 megapixel shot will expand on enlargement and you may notice little difference, but the larger you stretch the image, the more faults and flaws will show through.

As a general rule, the number of pixels required is determined by the size of the pictures that you wish to create.  Have a look at the table below to get an idea:

For a 300 DPI print (super sharp photo intended for viewing up close)
Print Size	Resolution needed for 300 DPI print
4x6	about 1-2 MP
5x7	about 2-3 MP
6x8	about 3-4 MP
10x8	about 4-8MP
13x20	about 8+ MP

As you can see, with the increasing size of the picture, the higher the megapixel count is. Do consider though, if you are going to develop large prints: are they going to be scrutinised closely? If they are in a frame on a wall, then the eye may not detect any minor imperfections.

The quick and simple answer is to choose somewhere in between, by making sure you have enough megapixels to get a good quality picture, and if it needs to be enlarged, that the quality can be maintained to your satisfaction.