TRG – Telescope Review Guide

Orion’s Skyquest XT4.5 is the smallest in their Dobsonian line of telescopes that includes the XT6 , XT8 , and XT10. Newcomers to the hobby are always surprised at how large amateur telescopes are, but to experienced observers, this XT4.5 is considered a very small scope. Tiny, in fact (It’s so small, astronomers are buying them just because they think they’re so cute). Make no mistake, though–the XT4.5 is a full-fledged telescope, and is a serious observing tool that could last you for years.

Your money buys you a lot in this case. Included are a good-quality 4.5″ f/8 primary mirror, two eyepieces, a finder, and a CD-ROM with a stripped-down version of The Sky, a software guide to the sky. The scope comes in two cartons. One contains the optical tube, and the other is a flat-packed box containing the base, which you assemble yourself. Orion includes all the hardware and tools you need, and the instructions are well written. Allocate about 30 minutes to assemble and align everything.

There are a couple of cost-cutting measures. The primary mirror is spherical, not parabolic (this is not likely to affect the views, however). Also, the focuser is plastic. Plastic focusers are naturally less robust than metal ones. Finally (and this may be the most serious concern of all), the scope is a little short for an adult. The eyepiece is only 3 feet off the ground, which may force you to stoop over (hint: try sitting on a short chair or stool while observing). On the other hand, the height is ideal for a child, making this a great telescope for kids.

Under the stars, the XT4.5 exhibits excellent performance. Once properly collimated (aligned), the optics give clear, sharp, contrasty views.  Jupiter’s cloud band and four moons are no problem to see, nor are Saturn’s rings. The Orion Nebula is a glowing fan of green gas, with a quartet of tiny stars at its core. Under dark skies (and with some diligence) the XT4.5 can even pull in some of the fainter deep sky objects, like the brighter galaxies in the Virgo Cluster.

As recently as a few years ago, the old adage regarding telescopes was that you must spend at least $300 to avoid buying junk. While this is still mostly true, Orion’s little XT4.5 breaks the price barrier in a big way. As long as you can deal with the short eyepiece height, it’s a great starter scope.

Last of a series

Your telescope

No matter what telescope you select, choose one that will meet your precise needs and interests. The planets, the Moon, and close stars require high power, good contrast, and sharp resolution, and if these are the objects of your attention, a refractor or reflector would be a good choice. Because very faint objects like galaxies and nebulae need a large aperture, you should invest in a big reflector telescope to view these. An all-purpose midrange telescope should serve best, for example a 6″ to 8″ reflector or an 8″ Schmidt-Cassegrain.

Keep checking back. Future articles will delve into filters used to cope with light polluted skies, astrophotography, astronomy book and software reviews, astronomical binoculars, and reviews of specific telescope models.