"Digiscoping" is the technique of using a spotting scope as a super-telephoto lense for digital photography. (Digital + Scope = Digiscope)

The camera is mounted onto the eyepiece of a spotting scope with a special adapter, as shown:

Depending on the size of the spotting scope, a digiscope can have an equivalent focal length of 800mm or more.

Despite the potential for digiscoping to be a lower cost alternative to super-telephoto camera lenses, there are several disadvantages including:

Small effective aperature - The aperture of a spotting scope is typically equivalent to a f/8 - f/11 camera lens. This significantly reduces the speed of the lens.

Lack of autofocus - Since spotting scopes lack a built-in autofocus mechanism, digiscoping is not suitable for moving subjects.

Atmospheric distortion - Although not usually discernible to the naked eye, distortions in the air (e.g. heat waves) between the scope and the subject can cause blurring.

Vignetting - An artifact of connecting a camera, which captures rectangular images, to a scope, which produces circular images in the eyepiece. The resulting dark corners in a digiscoped photograph can be minimized by cropping.

Nonetheless, under the right conditions, digiscoping can produce stunning photographs.

Copyright by Alexander Simon. For information about licensing photographs, please use the comment form. Last update 5/11/08.