Astronomy 101 - Part 2 - Binoculars

   Every amateur astronomer out for an evening stroll, or just lounging in a neighbor's backyard after a barbeque, has looked up at the night sky and wished for a small telescope to reach for. Orion is up. Or there's the Pleiades... M-31... Saturn... M-22... M-5. If only we had something portable and "totable" to look through... dang, it sure is clear tonight!

   You can't beat binoculars for portability and convenience. They will render very good images of a surprising multitude of celestial objects. For instance, with 8x42 binoculars, in fairly good skies, you can see the Orion Nebula, Andromeda Galaxy, many globulars, all the planets out to Uranus, and even a better (wider) view of the Pleiades than with most telescopes. There are over a hundred "binocular objects", and they are all on somebody's "list" on one website or another, i.e: - between the Binocular Messier Catalog.and others, there's at least 150 'easy' objects for small binoculars.

   There are things to look for when shopping for binoculars. Size matters. The first number (e.g., the "8" in 8x42) is the magnification, which in this case is 8-power. The second number is the diameter of the objective lens in millimeters. 8x42's are fairly common. We prefer 8x50's because it's the ideal configuration, but they are hard to find and very expensive from Swarovski and Leica.

   Also, pay attention to eye-relief specifications. Long eye-relief is okay if you wear glasses, but the emphasis on eye-relief is a common marketing mistake in our opinion, as many brands exhibit too much of it, to the extent that it becomes bothersome for astronomical viewing. There can be a point at which the entire field of view can be seen only if you hold the instrument AWAY from your eyes. We advise that you seek the opportunity to actually LOOK through them before you buy.

   A few stalwart folks use 10x50's, but a good 7x35 or 7x50 is fine also. We have even used "pocket-sized" 10x21's in a pinch. Anything more powerful than 8x50 can get tiresome and jittery with prolonged or sustained use, (the image can shake a lot more at 10-power) and some people, especially kids, will find it difficult to hold them still. Lens coatings are important, although for celestial observing you should NOT get binoculars with red-coated lenses.

   A wide selection of binoculars is available. The next time you're visiting friends for an evening barbeque would be a great time to have binoculars in the car.

Binocular Sources