Astronomy Spotting Scopes
Amongst more casual astronomy enthusiasts, the use of spotting scopes has become more prevalent in recent years thanks to their portability, ability to capture clear images and scenes, and the fact that they are often several hundred dollars cheaper than a conventional scope.
Designed mostly for terrestrial uses such as bird watching, hunting and digiscoping, the spotting scope is a rugged telescope designed to be used with or without a tripod, depending on the lens and eyepiece configuration. The biggest difference between a spotting scope and a telescope (from an imaging point of view) is that a spotting scope does not give you an inverted image.
A spotting scope is normally around 300-400mm long, with a lens of at least 60mm in diameter. Most lenses are between 60-80mm, though both larger and smaller lenses exist. A larger lens makes for a better, clearer image, while smaller lenses make the scope more portable and easier to use without a tripod. Most spotting scope eyepieces are set to a magnification of 25x-32x, but once again measurements either side of these values are available.
It is also possible to pick up spotting scopes with variable zoom lenses, but it is important to bear in mind that a high magnification results in a shortened field of vision, as well as limiting the light that can be captured by the scope and thus affecting the clarity of the final image. Some scopes can also be fitted to standard telescope eyepieces as well, increasing their versatility and range of use.
Spotting scopes are surprisingly good for viewing open star clusters, and heavenly bodies close to earth. They can also make for good planet-spotting scopes, under the right conditions.. However, for deep astronomy, such as spotting planetary moons, they are no match for the viewing power offered by a conventional telescope. When choosing one or the other, a good rule of thumb to follow is the 80/20 theory: If you plan to use the scope for terrestrial viewing 80 per cent of the time, and for stargazing for the remaining 20 per cent, then go for a spotting scope. However, if you’re looking for a wide range of functions such as electronic tracking, the ability to synch to a laptop or a sturdy semi-permanent mounting, or are purchasing the scope purely for astronomy, then you’d be much better sticking to a standard Schmidt-Cassegrain or Maskurov-Cassegrain telescope, as these make ideal entry-level astronomy scopes.
Bird Watching Spotting Scopes