Standard Lenses

The higher the focal length number, the more an image is magnified and the smaller the angle of view. A standard (or normal) lens is less wide than a wide-angle lens and so has a higher focal length number. The technical definition of a standard lens is one with a focal length roughly the same size as the diagonal measurement of the camera’s sensor. The practical upshot of this is that the focal length of a standard lens is different on full-frame, APS-C and Micro Four Thirds cameras. Standard lenses on these cameras are 50mm, 28mm and 24mm respectively. Happily, these  focal lengths are commonly available as prime lenses, though a zoom set to the relevant focal length will temporarily act as a standard lens.

You would be forgiven for shrugging your shoulders at the dry technical definition of a standard lens, and be wondering if there is more to them than that. Fortunately, there is. Standard lenses produce very natural-looking photos, without the dramatic distortions of space created by wide-angle and telephoto lenses. They closely match the perspective that we see the world, and are favoured by documentary photographers for this reason. If you only buy one prime lens then the standard lens for your particular camera system is highly recommended.