Not long ago, only one type of digital SLR camera was sold commercially. These were cropped sensor digital SLRs, with frames smaller than 35 mm. As of early 2011, three different types of digital SLRs are available.
Types--Cropped Sensor
For years cropped sensor was the sole type of digital SLR camera widely available. If a picture is taken with an identical lens on a standard 35 mm film SLR and a digital SLR with a cropped sensor, the cropped sensor camera will capture less of the same image, resulting in a picture that looks artificially zoomed in. This artificial zoom effect occurs at a factor of 1.6 times, meaning a 100 mm lens on a cropped sensor camera takes pictures like it's a 160 mm lens. Most digital SLR cameras still are of this type.
Types--Full-Frame Sensor
Full-frame digital SLR cameras do not have this zoomed-in effect. A full-frame camera has a multiplier effect of 1.0, meaning an image taken on it will look identical to that taken on a standard 35 mm film camera with the same lens.
Types--Four Thirds
The four thirds digital SLR format was introduced by Olympus. It is a cropped sensor camera. The principle behind it, however, is that any four thirds lens would work on any four thirds camera, regardless of the manufacturer. Previously, a Canon camera could only work with lenses made for a Canon camera, for example.
Tags: cropped sensor, cropped sensor camera, four thirds, sensor camera, Canon camera