These lenses increase the flexibility of a camera and allow for more creative pictures. The wide range of lenses that are available can sometimes overwhelm beginners. However, most lenses are not too difficult to understand and use. There are three basic types of lenses, Standard, Telephoto, and Wide Angle. There are also special features and converters that can be used in conjunction with these lenses for added range.
Standard lenses have a focal length that is equal in distance to the diagonal of the negative.
This distance for 35mm film is generally 45mm and for single lens reflex lenses it is anywhere from 445-55mm. Standard lenses have the unusual quality of reproducing an image exactly as it appears. These lenses are typically seen as a default lens and do not offer telephoto or wide-angle capabilities. They are also less expensive than lenses with added properties and make excellent basic lenses. A Telephoto lens has a focal length that is longer than 55mm but typically starts out at 70mm.