This article is intended to help parents, grandparents, aunts, uncles, etc. looking to purchase a telescope for that special little child that is fascinated by the night sky. As an amateur astronomer, active member in local astronomy club and facilitator of astronomy clinics, I believe I am well qualified to discuss telescopes for beginners.
Be Careful When Buying A Telescope:
Please be very careful when purchasing a telescope as a gift! I make this plea as I'm certain you do not want that special little person to be frustrated and unhappy with the gift you give them. Most inexpensive (less than $200.00 retail) telescopes that you can purchase at Toys-R-Us, Wal-mart, department stores, camera stores, etc. will fall into a category that many of us in the astronomy hobby reference as "trash" scopes. You can always spot these telescopes because they usually advertise their magnification power on the box (i.e. â€“ 575x, etc.). As a point of clarification, the main purpose of a telescope is not to magnify but rather collect light. Tasco, Jason, National Geographic, Vivitar, Bushnell, Cstar, Galileo and Edu Science are brands that sell in this cheap scope price point. Even the big boys like Meade and Celestron (that sell high end telescopes) sell in this cheap market area.
There are 3 major problems with these cheap telescopes.
First: Wobbly, Poor Quality Tripods/Mounts
With a wobbly tripod, even the slightest breeze or gentle nudge may cause the telescope to move even a little bit causing the object you are looking at to move out of the field of view. Also these poor quality tripods/mounts lack the ability to make small, minor movements in order to keep the object in the field of view so you can track it as the earth rotates. With these mounts/tripods, you end up jerking the scope around losing the objects from your field of view and having to find/center it again. Just as a point of reference, Jupiter, at medium or high magnification, will move out of the field of view within 30 seconds.
Second: Horrible Finders
A finder, which is mounted to main telescope tube, is a mini telescope with a much wider view of the sky that helps the user point the telescope to the spot in the sky you want to observe. Most finders on these cheap telescopes have lenses made of plastic and cannot be focused. When looking through the finder, the image is blurred and of almost no use. It's very, very difficult to point a telescope to an object in the sky just using the view from the telescope eyepiece. Typically the widest view you can get from one of these telescopes is around 1 degree. Now do the math with 180 degrees of sky in each direction, you're only looking at a very small patch of sky through the main telescope. If you don't have a good finder you will quickly give up in frustration trying to point the telescope.
Third: Poor Eyepieces and/or Diagonals
More often than not, these cheaper telescopes come with 0.965" diameter eyepieces. Often they'll be marked with a prefix of R, SR or H depending on the design. These designs are some of the oldest around, dating back to the 17th & 18th centuries and introduce a lot of optical problems that more modern designs have corrected.
The diagonal is a mirror that attaches to the back end of the telescope that creates a 90-degree shift in the light path so you don't have to strain your neck/back hunching over check out an image. Most poorly made diagonals scatter a lot of the light that you are trying to capture causing ghost images and difficulty achieving focus.
In summary, these cheaper telescopes will result not in a child that is inspired by the night sky but rather one that is frustrated with astronomy and that gift that ends up in the closet/garage collecting dust.
For more information, check out following good resources about telescopes on the Internet:
Purchasing a Telescope:
Cloudy Nights is one of the best resources for amateur astronomers out on the internet. There is a very helpful 3-part article titled "Starting Off Right in Astronomy" available: Part 1, Part 2, and Part 3.
Advice from the Raleigh Astronomy Club on purchasing a telescope is available in the article Purchasing a Telescope.
Already Have A Difficult To Use Telescope?
So what if you have one of these telescopes already? Don't lose hope, you can make the most of what you have:
And finally, my own experience with a my first telescope, a cheap trash scope:Â http://www.siriusastronomy.org/aboutme_mystory.htm.
Wishing you clear and steady skies!