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The amount of data we capture in each digital picture and the way we choose to store that information has a massive impact on what can be done with the image later on. The concepts of resolution and compression are ones we need to become familiar with.

In most situations bigger is better, and so it is on the surface with digital photography. What has become known as ‘resolution’ concerns how many pixels a camera uses to capture a picture – generally, the more pixels the better the quality of the finished result. A camera that has a seven million pixel sensor should produce images of a higher standard than a camera with just two million pixels.

If you think of a digital image as one created using coloured building blocks of an equal size you will be able to see that having a greater number of blocks will allow you to construct a more detailed picture.

Similarly, images made of more pixels can be printed to a larger size than those made with fewer. The crucial factor is how many pixels are needed to cover a certain area of paper to create a realistic impression of a photographic image and without the pixels becoming so enlarged they can be individually identified in the picture.

For standard printing purposes images need 200 pixels for every inch of paper the print covers. Thus for a 5x7in print we need at least 1000x1400 pixels in our image (5in x 200 pixels and 7in x 200 pixels) which means we need a camera that has at least 1.4 million pixels (1000x1400). If your image is bigger than 1.4 million pixels you will see an improvement in the quality of the print, but if you have less than 1.4 million pixels the picture will not look as good as it should.