We have picked a variety of 12 megapixel cameras where possible, with the exception of the 1inch sensor in the Nikon J1/V1, as this is a 10 megapixel sensor. Things to look out for include loss of colour as the ISO setting increases, loss of detail and edge quality, as well as any random colours appearing. Shown here are examples of what you can expect to see in regards to image quality and noise performance from different sensor sizes, each photo has been taken at ISO3200. Noise results from different size sensors: If you've ever wondered why sensor size is referred to as a fraction of an inch, then this is one of the best explanations around, and a much more useful indication would in fact be using the crop factor, or pixel size instead. For example, if you put an 18-55mm lens on a Canon EOS 600D with a 1.6x crop factor, you get the equivalent of a 28-88mm lens in 35mm terms. The crop factor is used to calculate what the effective focal length of a lens would be in 35mm terms based on the focal length printed on the lens. Mobile phones often use a smaller 1/3.2inch sensor, as do many digital camcorders.
Shown above is a relative diagram showing the size of many of the common sensors found in digital cameras, with the full frame sensor equalling the size of a 35mm film.