Choosing An Instrument To Fit Your Needs

Choosing An Instrument To Fit Your Needs

There may be a number of factors contributing to the decision to buy a particular telescope. The two most important factors are the purchaser’s budget and/or the type of observing for which the telescope will be used. Personally, I feel that the novice amateur astronomer should buy a suitable pair of binoculars before he/she gets a telescope.

Since a good pair of binoculars costs less than the cheapest astronomical telescope, you can find out whether astronomy is for you before you spend the extra money. Besides, I think you will be amazed at what you can see with a good pair of binoculars; that is, if you’ll put forth a little bit of effort in learning your way around the night sky. Before continuing our discussion of telescopes, let me further expound upon the merits of the lowly binocular.

Binocular Astronomy

Modern binoculars are much better astronomical tools than the first telescope Galileo used to make his earth-shaking discoveries. Lest you think these instruments are beneath your consideration, you should know that in 1995 someone actually discovered an unknown comet with a pair of binoculars! To be sure the discoverer of this comet was an observer with some years of experience and his binoculars were fairly expensive, but even he was once a novice such as you are now.

All right, what can you, the rank amateur expect to see with a low-cost pair of binoculars? For starters: manned and unmanned spacecraft, plasma clouds from meteors, craters on the moon, the major moons of Jupiter, known comets, asteroids, star clusters, nebulae (interstellar gas clouds), even a galaxy millions of light years away! Observing with binoculars is more comfortable because you get to look with both eyes instead of just one. Again, just as with telescopes, you need to know how to tell which pair of binoculars will make a good astronomical instrument and which will not.

While binoculars with 35 mm objectives are usually suitable for observing large features on the moon and the major satellites of Jupiter, 50 mm objectives will yield a brighter image and a larger field of view when observing deep sky objects. As is the case with telescopes, bigger objectives mean better views. If deep sky objects are to be your sole pursuit, 7x magnification on 50mm binoculars will serve you better than 10x. Remember, the lower the power the brighter the image! 7x50mm binoculars were originally used for nighttime security and surveillance (before electronic night vision scopes were invented). The more common 10x50mm is better suited for observing the moon, though it is still a much better deep sky instrument than the smaller 35 mm.

If you’re willing to pay a little more, you can get a pair of zoom binoculars yielding a wide range of magnifications. For 50 mm binoculars, I recommend that the lowest magnification be 8x or lower if deep sky objects are your interest. Many 50 mm zoom binoculars reach magnifications of 15x or higher, making them well suited for revealing mountain ranges on the moon as well as smaller craters. Such a higher power would also allow observation of the phases of the planet Venus.