Salutations, celestial sight-seers! I'm David Fuller, host of Eyes on the Sky.
For thoseof you that don't know me, I do videos that help people find things in the night sky withsmall telescopes and binoculars.
And one of the questions I often get is, "What do youthink of this telescope?" "Should I buy it?" With the holidays approaching, as I'm makingthis 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 recommendnow 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.
Whatmost 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 slightlydifferent features, they all probably originated out of the same location in China.
So thebrand itself very often does not matter.
So I won’t talk much about brands, but rathertypes of telescopes to strongly consider buying.
What that also means is that today, the main optical element of most telescopes is prettygood.
Whether that be the lens in a refractor or the mirror in a reflector, odds are theyare above average quality for most astronomical telescopes you would find from most reputable dealers .
However, marketers of telescopes know that you are looking atbuying a telescope that is under a very specific price point.
So what has happened is that almostALL 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 theprice 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 opticaltube with that above-average main optical element – are on some very poor, shaky mountswith some really underperforming accessories like 2 element eyepieces and stopped-downbarlow lenses.
Because how can you aim a telescope with a finderscope through which you can’tsee anything? How can you use higher magnification on planets if the aluminum legs are so thinthe telescope wobbles at the slightest breeze? How do you aim it at Jupiter or Saturn whenthe 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 fewtimes, because people will think they are hard to use (and for those compromised telescopesystems that are inexpensive, they will be right!).
So unless you want to spend a lot of time fixing a wobbly, hard to aim telescope withcheap eyepieces and finderscopes you’ll need to upgrade anyway, here are a few solidtelescope 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 arefairly 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 lighterand therefore easier to move around, by most anyone.
Two, a reflector MUST have good collimationin 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 slightmis-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 userSo the smaller mirror is balanced out by being able to achieve better images at the eyepiecewith a more forgiving focal ratio.
Third: A 6” f/8 has a 1200mm focal length.
If itcomes with a 9mm or 10mm eyepiece, you’ll have adequately decent views of the Moon andplanets, not to mention deep sky objects in that or a longer focal length one.
Do these telescopes run above $300 or so? Yes theydo.
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, evenwith inexpensive eyepieces.
If you need to go a little smaller or less expensive, consider a 4.
5” / 114mm f/8 Dobsonianreflector.
You may need to set the base on a small crate to get it high enough up foreasier viewing, but with a 900mm focal length and a 10mm eyepiece, you’ll be able to seethe 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 hasenough 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 little76mm tabletop Dobsonian reflectors.
I reviewed these here on YouTube and on EyesontheSky.
I prefer the Orion Funscope because it comes with a red dot finder and two inexpensiveeyepieces, but those eyepieces aren’t the cheapest possible option another brand useseither.
They actually useful eyepieces.
There’s two things you won’t get with this telescopethough.
1) You're not going to get a good table to put it on, so make sure you have one or make my “SuperSimple 2x4 tripod” if you’re handy with wood-cutting tools and 2) The other thing you won’t getis 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 magnificationto see the planets well.
But don’t think this telescope isn’t capable; I’ve beenable to see the Crab Nebula and the two galaxies in Ursa Major, M81 and M82 with it! It’salso a great gift for kids interested in astronomy, because this telescope is easy for small handsto pick up and move.
You will see a lot of the optical aberration called “coma” inthis 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 tosee a lot, and many of the ones that are larger are on mounts that are too small (or too expensive!), so the shakinesswill make it impossible for you to see much.
And notice I did not mention any computerizedtelescopes.
I can’t tell you how many people I’ve tried to help with those telescopesbecause they seem like a great idea “They’ll point themselves for you!” What is oftenmisunderstood is if you can’t align that telescope initially, you will be able to pointat the Moon or Saturn with your finger in the sky, but never be able to aim your telescope at it.
PLEASEavoid 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.
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 significantcompromises built into it.
So either bite the bullet and spend a little extra, or go withthe small, stable, easy to use telescope and learn more about what might really work foryou 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 degreesapparent field of view, making higher magnification much more comfortable.
Or, if you have a stableenough telescope like a Dobsonian, consider splurging a bit and getting an Explore Scientific82 degrees apparent field of view 4.
7mm or 8.
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.