Astronomical Observing 101 (or before) Part 4

doorgunnerjgs

Shared on Wed, 10/15/2008 - 17:09

Well, it's been a while (like almost a month), but then again, no one has complained. So here we go with telescopes. Although the tube (actual telescope), is very important, the mount is equally important. They fall into two basic categories, altazimuth and equatorial.

Altazimuth allow changes in altitude (up and down) and azimuth (around and around) similar to a camera tripod. One very popular mount is called the Dobsonian named after a California amateur astronomer, John Dobson.

Equatorial mounts allow a smooth tracking of objects as the earth rotates beneath a stationary sky. (I know it looks like the sky is moving, but it really is the earth). These types of mounts allow long exposures of objects with a camera when equipped with a motorized drive (or very steady hand on a manual control).

Either type of mount can optionally be found with "GOTO" capabilities. This means that, after a proper setup, a computer can automatically point the telescope to a specific object (star, nebula, planet, cluster, galaxy, etc.).

Please note that the recommendations are not all inclusive! I own two Orion scopes and two Meade scopes. That doesn't mean that other manufacturers are worse, just that I've come to like what I have. Celestron (now an arm of Meade, or vice versa), Sky-Watcher USA, Tele Vue, Astro-Tech, and others make good quality scopes to fit a lot preferences.

Newtonian Telescopes

Least expensive for the amount of light gathering primary mirror, these can be found in sizes from around 4.5 inches up to 17.5 inches! Prices range from as little as $180 to as much as $4,000. Mounts are generally altazimuth but not in all cases. In addition, some are offered on "GOTO" mounts.

For beginning amateur astronomers, a small Newtonian on either kind of mount is a great way to start. Orion Telescopes (at www.oriontelescopes.com) makes some really nice ones, affordably priced. One that was tested by Sky and Telescope in their September, 2008 issue was a 6" telescope called the StarBlast 6 with two decent eyepieces on a Dobsonian mount. The included eyepieces are 25mm (30x) and 10mm (75x). A great starter at a reasonable price, $250.  Edited to add cost!!!

If you want something cheaper, then look into an 4.5" from Orion, the SkyQuest XT 4.5" Dobsonian at $190. I wouldn't go any smaller than this and don't REALLY recommend it since with the smaller aperture, it won't give you the views that you can get with the larger scope.

Schmidt-Cassegrain

These are generally larger scopes but easily transported due to the "folded" light path used. They are often fairly heavy (around 70-80 lbs or more with tripod), especially when mounted on their tripods. They generally range in size from 8" to 14" and from a $1,000 on up and can be found on both altazimuth and equatorial mounts. Most are "GOTO" scopes and the ones on equatorial mounts are good for photography.

Celestron and Meade are the primary manufacturers of these. I have an old Meade LX-50, 8" that I added "GOTO" capability to and got the equatorial mount for it. Today, the LX-90 is comparable and goes for about $2,100.

Maksutov-Cassegrain

These are generally compact, smaller scopes (about 15 lbs without tripod) primarily manufactured by Meade, Celestron, and Orion. For a while, the most popular were the Meade ETX series although the other ones have made inroads in there sales. The original ETX was a 90mm version but a 102mm and 125mm were added. Now they range from 90mm to 180mm. One of the earliest telescopes of this type was the Questar 90mm, which currently start around $4,000. Others are priced from around $400-900 on up.

I have a Meade ETX-125 that currently goes for about $900 on sale (list $1800).

There are a lot places to buy these and the number of scopes available is mind boggling. I generally buy from OPT (Oceanside Photo and Telescope in Oceanside, CA, www.optcorp.com) because I have had good luck on prices and they have given me excellent service. Orion (OrionTelescopes.com) sells direct (I have two of their scopes) and have been very reliable. My first Meade was purchased from Astronomics (Norman, OK, www.astronomics.com). They gave good service and reasonable prices but I still prefer OPT. Some of the other big names are Scope City, Woodland Hills, and Wolf Camera.

The important thing is to shop around, get familiar with the type of scope you want, and who can give you the best price with good service.

Next up: Accessories - You can and probably will spend more on accessories than on your telescopes. What are they and what are they good for? Stay tuned for a future installment!

Comments

doorgunnerjgs's picture
Submitted by doorgunnerjgs on Thu, 10/16/2008 - 19:11
p.s. I edited the article to add the cost of the 6" Orion telescope, $250.
Devonsangel's picture
Submitted by Devonsangel on Wed, 10/15/2008 - 17:32
Staying tuned!
Trashguy's picture
Submitted by Trashguy on Thu, 10/16/2008 - 02:03
Once upon a time....I really wanted to build a telescope. But, when you're a little kid who's always broke, stuff like that just...drifts away from you. Then, as an adult more important stuff comes along...and it drifts away some more. :-(

Join our Universe

Connect with 2o2p