There exist a multitude of guides on the book market about what can be seen in the sky with a telescope, some of which sights we have discussed in past installments of this column. I’ve used some of the largest telescopes in the world in my career as an astronomer, but many of my most memorable observing experiences have been with small telescopes only a few inches in aperture.
So the emphasis this month is on the virtues of such glasses themselves.
There seems to be an unspoken but widely accepted mantra today that “bigger is better,” whether regarding houses, boats, sports stadiums—and in our case here, telescopes. Some amateur astronomers have observatory-class instruments housed in their backyards or trailer-mounted to take to dark sky locations and to star party gatherings. But there is a proven rule-of-thumb in casual astronomy that the smaller the telescope, the more often it will be used. One reason has to do with weight and portability. Having to lug a heavy telescope outside and then back in at night can dissuade even the most enthusiastic stargazer. Then there is the issue of “cool-down time” with larger instruments. The optical glass in telescopes requires time to acclimate to the outside temperature before delivering good images. And the larger the telescope, the more glass there is to cool. Small scopes are normally ready to use within minutes of taking them outside. Also, larger ones with their higher powers give somewhat of a tunnel view of the sky compared to small ones. These typically work at lower magnifications, which enables them to take in a wider field of view making them easier to use. (This is all a result of the eyepiece design.)
Interestingly, many stargazers start out with a small instrument, as we are recommending here. But then “aperture fever” sets in and they go for a much larger one. Alas, it often happens that sooner or later they return to their smaller scope because it’s much more convenient to use. Considering all of this, the Scientifics 60mm (2.4-inch) refractor makes an affordable and good choice as a telescope to begin with.
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of 10 books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.