Trade Tricks: Digiscoping
Achieve high magnification with a digital camera and spotting scope
Photographing wildlife or the Little League left-fielder at a great distance can be a challenge, especially if you don't have the deep pockets to afford a large super-telephoto lens of 600mm or higher. All hope isn't lost, however; digital photography gives us the benefit of high magnification through digiscoping.
Digiscoping is a form of photography that combines a digital camera with a spotting scope, a portable telescope designed for viewing terrestrial subjects. Spotting scopes offer the focal-length equivalent of 1,000 millimeters and higher when used in conjunction with a digital camera and eyepieces from 20x to 60x magnification.
Popularized by birding enthusiasts, digiscoping places the lens of a digital compact on the scope's eyepiece. The camera's automatic focus and metering systems deliver a detailed, well-exposed image that you can enlarge.
The first step is to attach a camera to the scope's eyepiece. A 30x eyepiece is recommended. Compact digital cameras with lenses that feature a filter thread may work with an adapter (such as the Adorama T-Thread Adapter) to provide the bridge between the scope and the camera. For cameras without a filter thread, there are other devices that make the connection utilizing the camera's tripod socket or lens barrel. These devices are available through the spotting-scope or camera maker or independent manufacturers.
When the camera's lens opening is smaller than that of the exit pupil of the scope's eyepiece, you'll experience vignetting, or shadowing in the corners of the frame. To eliminate this problem, zoom in until the shadows disappear from the image's corners. A camera with 3x to 4x zoom is recommended. Avoid using digital zoom as this reduces image quality.