ACHIEVE HIGH MAGNIFICATION WITH A DIGITAL CAMERA AND SPOTTING
SCOPE
By Ibarionex R. Perello
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.
Besides lens magnification, consider the resolution of your
camera. Virtually any current digital camera delivers good-quality
4x6 to 8x10 prints, even with a modest resolution of 3 megapixels.
A higher-resolution camera allows you to make bigger enlargements,
such as 11x14 or 13x19.
Although digiscoping achieves very high magnification, the subject
still may take up a small portion of the frame. In such photos,
crop into the image so the subject fills the frame. Using a
camera with 5 to 8 megapixels of resolution, you can crop the
image but retain enough data to produce a good-quality enlargement.
Focus and exposure are handled automatically via the camera’s
exposure and focusing systems. The immediate playback feature
confirms that both are accurate. A camera with a manual exposure
mode or exposure compensation is a plus, particularly with a
challenging subject such as a white egret whose color and tone
could fool the meter into a severe underexposure.
A solid tripod is a must. The slightest camera shake results
in a soft image, even if you’re using a fast shutter speed.
A tripod head that provides smooth movement, such as a fluid
head designed for video, is advantageous, especially when tracking
a moving subject.
Many photographers also use the camera’s self-timer if
the subject isn’t moving. Additionally, third-party manufacturers
offer adapters that allow remote release with virtually any
digital compact.
