Salutations, celestial sight-seers! I'm David Fuller, host of Eyes on the Sky. For those
of you that don't know me, I do videos that help people find things in the night sky with
small telescopes and binoculars. And one of the questions I often get is, "What do you
think of this telescope?" "Should I buy it?" With the holidays approaching, as I'm making
this I thought I'd make a couple recommendations you should strongly consider.
I’m going to share a few secrets about good and bad telescopes, and a couple that I recommend
now knowing anything about your financial situation, local light pollution situation,
or ability to move a telescope to darker skies. So let’s start with a few badly kept secrets.
One, most telescopes today are made in China. That’s not really news to most people. What
most people don’t know is that most of the telescopes are made in just a few factories.
So while you may see 2 or 3 or 4 different brands of a similar telescope with slightly
different features, they all probably originated out of the same location in China. So the
brand itself very often does not matter. So I won’t talk much about brands, but rather
types of telescopes to strongly consider buying.
What that also means is that today, the main optical element of most telescopes is pretty
good. Whether that be the lens in a refractor or the mirror in a reflector, odds are they
are above average quality for most astronomical telescopes you would find from most reputable dealers . However, marketers of telescopes know that you are looking at
buying a telescope that is under a very specific price point. So what has happened is that almost
ALL of the other important elements of the telescope, at least in the very inexpensive models – for example, the stability of the tripod,
the quality of the eyepieces, finderscope, the smoothness of the motions to aim the telescopes
– they are all compromised on telescopes below a certain level in order to meet the
price they know you want to pay.
And that’s bad for you - or the person getting the telescope.
So here’s another secret, those decent optical tubes – that is to say, JUST the optical
tube with that above-average main optical element – are on some very poor, shaky mounts
with some really underperforming accessories like 2 element eyepieces and stopped-down
barlow lenses. Because how can you aim a telescope with a finderscope through which you can’t
see anything? How can you use higher magnification on planets if the aluminum legs are so thin
the telescope wobbles at the slightest breeze? How do you aim it at Jupiter or Saturn when
the motions are jerky, and not smooth? That’s’ a recipe for frustration. And believe me,
I’ve been there! I’ve owned telescopes like this.
That means a lot of otherwise decent telescope tubes will never get used more than a few
times, because people will think they are hard to use (and for those compromised telescope
systems that are inexpensive, they will be right!).
So unless you want to spend a lot of time fixing a wobbly, hard to aim telescope with
cheap eyepieces and finderscopes you’ll need to upgrade anyway, here are a few solid
telescope choices you can have confidence in from the very beginning.
A large number of amateur astronomers, when asked, “What telescope should I buy?”
suggest an 8” - or 200mm diameter aperture - f/6 Dobsonian reflector. And that's not a bad recommendation for most people who are
fairly well-to-do as far as far as their health, and can move the telescope easily and have some pretty decent means in terms of financial situation.
But I'm going to recommend one size smaller, and suggest a 6” f/8 reflector instead, and here’s why: One, it’s a little lighter
and therefore easier to move around, by most anyone. Two, a reflector MUST have good collimation
in order to provide an a good image at the eyepiece. That's the aiming of the mirrors so they are in allgnment with each other. An f/8 focal ratio is more forgiving of slight
mis-collimation than an f/6, and that 8” f/6 is a bit more difficult to collimate is not going to be as good for the uninitiated user
So the smaller mirror is balanced out by being able to achieve better images at the eyepiece
with a more forgiving focal ratio. Third: A 6” f/8 has a 1200mm focal length. If it
comes with a 9mm or 10mm eyepiece, you’ll have adequately decent views of the Moon and
planets, not to mention deep sky objects in that or a longer focal length one. Do these telescopes run above $300 or so? Yes they
do. But that is an investment than can easily last 10 years or more with a little care. So that's $30 a year!
That's a pretty inexpensive hobby. It’s well worth that money. And finally, an f/8 system will provide good views, even
with inexpensive eyepieces.
If you need to go a little smaller or less expensive, consider a 4.5” / 114mm f/8 Dobsonian
reflector. You may need to set the base on a small crate to get it high enough up for
easier viewing, but with a 900mm focal length and a 10mm eyepiece, you’ll be able to see
the rings of Saturn and the Andromeda galaxy too in a longer focal length eyepiece. Priced at around $250 from several retailers,
it’s a solid option that won’t wobble, is also forgiving on collimation, and has
enough aperture that many younger eyes will see some color in the Orion Nebula as well.
And lastly, if those two options are still out of your price range - or if you're looking for someone who is a little younger - consider the little
76mm tabletop Dobsonian reflectors. I reviewed these here on YouTube and on EyesontheSky.com.
I prefer the Orion Funscope because it comes with a red dot finder and two inexpensive
eyepieces, but those eyepieces aren’t the cheapest possible option another brand uses
either. They actually useful eyepieces. There’s two things you won’t get with this telescope
though. 1) You're not going to get a good table to put it on, so make sure you have one or make my “Super
Simple 2x4 tripod” if you’re handy with wood-cutting tools and 2) The other thing you won’t get
is enough focal length to view the planets well. So you WILL need to buy a decent,
3x barlow lens either immediately or on the future in order to get up to about 90x magnification
to see the planets well. But don’t think this telescope isn’t capable; I’ve been
able to see the Crab Nebula and the two galaxies in Ursa Major, M81 and M82 with it! It’s
also a great gift for kids interested in astronomy, because this telescope is easy for small hands
to pick up and move. You will see a lot of the optical aberration called “coma” in
this telescope - BUT! - that doesn’t affect the view in the middle ½ to 2/3 of the view. Which is where most people look anyway.
Notice I have not included any small refractors – that’s because most are too small to
see a lot, and many of the ones that are larger are on mounts that are too small (or too expensive!), so the shakiness
will make it impossible for you to see much. And notice I did not mention any computerized
telescopes. I can’t tell you how many people I’ve tried to help with those telescopes
because they seem like a great idea “They’ll point themselves for you!” What is often
misunderstood is if you can’t align that telescope initially, you will be able to point
at the Moon or Saturn with your finger in the sky, but never be able to aim your telescope at it. PLEASE
avoid these telescopes as a first one!! I just don't think they're a good option for your first one.
I do have some other telescopes I don’t mind recommending listed on my website, eyesonthesky.com. and I put a link to them in the video description here on YouTube.
Keep in mind anything under about $250 to $300 is probably going to have some pretty significant
compromises built into it. So either bite the bullet and spend a little extra, or go with
the small, stable, easy to use telescope and learn more about what might really work for
you in the future.
Oh, and if you already have a small telescope? Here’s a couple eyepiece recommendations:
Consider the Expanse 9mm or 6mm eyepieces from Orion Telescopes, that have a 66 degrees
apparent field of view, making higher magnification much more comfortable. Or, if you have a stable
enough telescope like a Dobsonian, consider splurging a bit and getting an Explore Scientific
82 degrees apparent field of view 4.7mm, 6.7mm or 8.8mm eyepiece. I have the 4.7 and 8.8,
And I REALLY like them. So I hope that will help you with your holiday buying options this year.
Keep your eyes on the sky, and your outdoor lights aimed down, so we can all see, what's up!
I'm David Fuller, wishing you clear and dark skies.