Last updated: 1 January 2001

What to Expect from Your Small Telescope?

So you are thinking about purchasing an ETX but you wonder just what exactly can you see with it and how easy it is to use. First off, forget about all those really neat Hubble Space Telescope astrophotographs, 200" Palomar Telescope astrophotographs, and even those really beautiful CCD astrophotographs taken with 10" telescopes. Even if you could look through the eyepiece of those telescopes, what you would see would not match the details and colors which you see in long duration exposures or CCD images. OK, so you won't see swirling nebulae in multiple colors nor distinct clouds on Mars, can you take these kinds of photographs? The truth is "not really" although you can see some photographs on the ETX Astrophotography pages that show just what can be accomplished with the right equipment and lots of patience. OK, so you can't see all these incredible details and you can't photograph them either, why get an ETX?

There are two great qualities of the ETX: it is small (meaning "portable") and optically, it is incredible for its size. You can see cloud bands on Jupiter and perhaps Saturn (on a good night), the Rings of Saturn, some moons of Jupiter and Saturn, phases of Venus, some hints of dark areas on Mars (and the Polar Ice Cap during a good opposition), some galaxies and nebulae (fuzzy though they will appear), double stars (some very beautiful), the Moon, and with the proper protection, the Sun. If you try, you can actually see a lot with the ETX. Yes, you could see and photograph more details and colors in objects with a larger (much larger, actually) telescope so why not get a larger telescope?

If you can get one AND you will use it, great, go for the largest telescope you can afford and use. I stress "use" because many amateur astronomers get excited about having a large telescope but then discover that it is not convenient to actually move it outside, set it up, use it, move it back inside, and store it. Very quickly large telescopes go unused because they are not convenient to use on a moment's notice. The ETX is extremely portable and with its high optical quality, you will be able to use it on a moment's notice AND you will want to. One other consideration for those new to the science of Astronomy: it takes some work to really enjoy it. You have to study the skies to know your way around. You have to read books, get some star charts or star charting software, and learn the language. This is not difficult nor do you have to be expert in it. Having the convenience of the ETX actually makes learning the skies more productive. Someday, you can move up to a larger scope as your enjoyment of Astronomy increases (along with your bank account) but you can still use the ETX on trips or for those spur-of-the-moment observing sessions.

Learning a new telescope while trying to learn your way around the sky can be a difficult task for some new users. Al (acl3@sprynet.com) offers the following valuable tip for new users:

Although I have had a good bit of experience using a terrestrial spotting scope, I found the new ETX on the fork mount awkward. The problem was, at least for me, doubly difficult because the learning was done literally "in the dark".

I decided to familiarize myself with the scope itself without the fork mount. Mounting the scope, directly to the Bogan panhead used for the spotting scope, I was again on familiar ground. Without the complexities of the fork, I am learning about the fields of view, reversed image, multiple eyepieces, locating astro objects, etc.

With some additional time learning the scope, I plan on going back to the fork mount. However, some may find the two step approach:

1. Learn the mechanics of the scope, and then
2. Learn the use of the scope in the fork mount,

to be an easier transition from their conventional terrestrial spotting scope experience.

When the above comments were written back in 1998, the only ETX model available was the 90mm original ETX Astro. Since then many new models have appeared, along with the DS line of telescopes. These have apertures ranging from 60mm to 127mm and focal lengths from 350mm to 1900mm. While much of the above it still true, based upon recent questions that have been sent in and posted, it is apparent that there are many new telescope users who are not certain just what to expect from their small telescope. So, I have decided to collect some additional comments here.

1. Read the comments above that pertain to the original ETX. Much is still applicable.

2. Stars will not show disks like most of the the planets in our Solar System. They are just too far away.

3. With all the current line of ETX and DS telescopes you can see craters on the Moon, cloud bands on Jupiter, some moons of Jupiter, the Ring around Saturn, perhaps one moon of Saturn, phases of Venus, brighter nebulae, brighter galaxies, double-stars, star clusters. Some stars will even show a nice color (typically blue, yellow, or red).

4. There are limitations in magnification (power) that you can use with any telescope. Keep in mind that the theoretical maximum magnification is double the telescope aperture in millimeters. So, for the ETX-60AT that would be 120x. To determine what focal length eyepiece would yield that magnification, you can use the formula:

  eyepiece focal length = telescope focal length / max magnification
With good optics and bright objects many users have exceeded this theoretical maximum. To calculate the magnification that an eyepiece will yield with your telescope use this formula:
  magnification = telescope focal length / eyepiece focal length
5. Sometimes a high power is not what you need. Many extended objects, especially star clusters, may look better in lower power and/or wider field eyepieces.

6. You can take photographs with any of the telescopes. You may have to work at it and in most cases don't expect Hubble-like images to result. Long duration astrophotography is normally not possible with these consumer telescopes, although you can get reasonable results by piggybacking a 35mm camera on the telescope and guiding the telescope on a star or other object. See the Astrophotography galleries on this ETX site for many fine examples of what you can do.

7. Whenever you have questions, do some research. You'd be amazed what you can learn by searching for information. You will learn so much more and more quickly than just by asking questions. There is a TON of user-supplied information on this ETX site. Try the "search" feature; it isn't perfect but will many times help you find answers. Of course, if you can't find the answers, ask the questions. Someone will likely be able to help.

8. As long as your expectations match the capabilities of your telescope you won't get frustrated. But if you have bigger eyes and a bigger wallet, get the largest telescope you can afford AND will use. The best telescope is no good sitting in the closet because it is too bulky or inconvenient to set up for use.

9. Finally, enjoy this hobby. Amateur Astronomy is fun, educational, challenging, and rewarding. Many have spent their entire life enjoying it and learning. If you have just joined us, welcome aboard. You have much to experience; don't expect to take it all in during your first night out.

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Copyright ©1996-2001 Michael L. Weasner / etx@me.com
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