So I have been about it for some time now. I am getting ready to order my first telescope. I’d like to view the planets and moon and look at some deep sky objects. I have been dong some reading online, and so far this is what I am looking at:
Orion 8945 SkyQuest XT8 Classic Dobsonian Telescope Amazon.com
Meade Instruments 07199-2 Series 4000 8 to 24-Millimeter 1.25-Inch Zoom Eyepiece Amazon.com
Astromania 2" ED 2X Dual Power Telescope Barlow Lens Amazon.com
I understand this is not top of the line. But I think for my use this will be good. I also am thinking of getting a moon filter and maybe a solar filter.
And I don’t want to buy a smaller telescope to start with, because I think I would quickly get board with it.
I started with astronomy binoculars and never felt the need to get a full fledged telescope.
I got this one
Celestron - SkyMaster Giant 15x70 Binoculars - Top Rated Astronomy Binoculars - Binoculars for Stargazing and Long Distance Viewing - Includes Tripod Adapter and Case
I am not trying to be snarky by saying this, but there are already a lot of threads on this question (some of which contain lists of previous threads on it). I think searching the phrases/words “first telescope” or “buying a telescope” would yield a lot of helpful and relevant information.
The main decision you must take early on is if you want to simply observe, or if you want to get into astrophotography too. If you want to just observe, the Dobson mount that the telescope you linked to has is fine. If you want to take pictures (of anything fainter than the Moon), there is no way you can avoid getting an equatorial mount, fitted with either tracking motors or (preferably) a full-fledged electronic goto (an electronic dial where you select the object you want to view, and the mount aims for it automatically). I personally prefer equatorial mounts also for visual observations, but that’s a matter of taste; common lore is that most beginners prefer Dobson mounts initially.
This is an important decision to make, as the mount can be more expensive than the tube with the actual optics in it.
It looks like you already know the first lesson, which is to get quality optics (the key word to look for is “diffraction-limited”). Meade, Celestron, and Orion all meet this standard.
The second point is that aperture is king. No matter what you’re hoping to observe, bigger aperture is always better. The only limiting factor here is your budget, because big optics get expensive fast.
And the mount can be significant. Dobsonian mounts are cheap and easy to set up, but you absolutely cannot do any decent astrophotography with one. Some scopes come with a computerized alt-az mount that can automatically find and track any object in their database, and that can be convenient, but it still can’t be used for photography. For photography, you absolutely must have an equatorial mount, and those are significantly more expensive than alt-az (and also more trouble to set up, if you don’t have a fixed observatory).
Also, if you live in a light-polluted region it can be nearly impossible to find deep-sky objects unless you have a GOTO mount.
If you are primarily focused on planets and the moon, then something like an 8" Schmid-Cassegrain on an equatorial mount is the way to go. If you want to do primarily deep sky observing, and you don’t care about astrophotography, the Dobsonian is fine, Yoh will even be able to photograph the Moon and bright planets with it, although it will be a pain as without a motorized tracking mount the targets will be constantly moving in your field of view.
Robert Evans, astronomer and minister holds the record for detecting supernovas (his competition is large telescopes with computers). His preferred telescope is a 31cm Dobsonian.
Thank you for the replies. I really wanted conformation that what I was planning on buying isn’t crap. And I’m not planning on any photography. And the equipment for it would be quite a bit over budget.
And so, there shouldn’t be any problems with using the zoom eyepiece and the 2x eyepiece? I know people usually but separate eyepieces for different magnifications, but for the zoom eyepiece should be good for general use, correct?
And how well would such a scope travel in the back of a pickup truck? If strapped down properly, is there any danger of damaging the mirrors or anything? And is a collimation laser worth buying?
I don’t have my own experience with zoomable eyepieces; but in a hobby astronomy Facebook group that I’m a member of people often ask similar questions about equipment, and the consensus view in the group seems to be against such eyepieces. The idea is that they’re not really optimised for any particular focal length, and that you’d be off better, in terms of optical quality, with a set of eyepieces each for a given focal length. But again, here I can’t speak out of experience.
As for magnification, you can compute magnification by dividing the focal length of the telescope (or its main mirror, to be precise) by the focal length of the eyepiece. So if you get, for instance, a scope with a focal length of 750 millimetres (30 inch), and put in a 20 millimetre eyepiece, you will have a magnification of 750/20 = 37.5; with a 10 millimetre eyepiece, 75, and so on. The Barlow lens acts as if it doubled the focal length of the telescope, so it also doubles the magnification. Which sounds good because it means that, in principle, you can achieve any desired magnification with any telescope by simply putting in an eyepiece with low focal length. But don’t be fooled; as Chronos has said, the main parameter indicating the power of a telescope is its aperture (because it is aperture that collects and focusses light). If you aim for too much magnification with a telescope that does not have enough aperture, all you end up with is a highly magnified but dark image that is highly susceptible to flurry air.
A Dobsonian does fine in the back of a pickup truck. You just want it to be secured so the optical tube assembly won’t roll around back there.
As for collimation, I’d suggest getting both a combination sight tube/Cheshire eyepiece and a laser. One glitch you may well run into is that many laser collimaters arrive out of alignment and have to be collimated themselves before they can be used to collimate a telescope. I recommend this Cloudy Nights thread for learning more about collimation: How To Collimate Your Newtonian.
You’ll have fun with whatever scope you get! Telescopes are like potato chips; you’re never satisfied with just one.
If you are going yo be a visual observer, don’t skimp on the eyepieces. It’s easy to get caught up in aperture envy, but without a good eyepiece you may wind up with narrow fields of view, poor eye relief and opticsl distortion that will make viewing difficult and uncomfortable.
I do mostly astrophotography, but for occasional live viewing I bought an Hyperion 20mm eyepiece, and it is just dramatically superior to the Plossls I had that came with my scopes. For a visual observer, get at least one mid-power high quality eyepiece.
Expect to spend around $200 for a decent eyepiece. If you get into top brands like Teleview, you can easily spend $500 on an eyepiece, but tgat would be overkill for your setup.
As the others said, don’t focus on magnification. For deep sky, there are plenty of objects that don’t need much magnitication at all. In fact, some of them, like Andromeda, won’t even fit in the field of view of my scope, even with my focal reducer. First use low magnification and learn the night sky and how to get around it. High mag for planets and the moon only.
Any recommendations? Only thing I wish is that they had right angle view finders.
And I am going to look into better eyepieces as well. And I have been reading threads on other message boards about it, but I figure I’ll ask here. I’d like good eyepieces for viewing the moon and planets, as well as Andromeda and other deep sky objects. What focal lengths and field of view should I be looking at?
You can always upgrade to a right-angle viewfinder, but they aren’t as easy to use as you might think (as you’re looking down rather than at the sky when you’re using it). Get one that offers a right-angle correct image when you upgrade, so you don’t have to mentally flip the image around to get it to align with your star chart.
One upgrade I would STRONGLY recommend is installing a Telrad alongside whatever finderscope you go with. A Telrad makes finding your way around the sky 1000% easier, whatever finderscope you’re using.
Eyepieces are very much a matter of taste. I’m happy with Plossls, but a lot of people like newer designs that offer a wider apparent field of view. The eyepieces that ship with the Dobs are OK, so use those first while you learn about the many upgrade options available. As for focal lengths, I’d suggest starting with a 25 mm, a 20-8 mm zoom (the Hyperion one is good), and then something in the 6-4 mm range for those rare occasions whn you can use truly high power (buy this one LAST, as you’ll rarely use it). (Don’t go too low on your focal lengths, or you’ll start to see the shadow of the secondary mirror popping up in your field of view, which is annoying.)
Agreed, Telrads are great. Back when I was active in the hobby (ah, to be under Montana skies again!), I mostly just went straight from the Telrad to the main eyepiece, skipping over the finder scope, and occasionally skipped the Telrad, too, and just sighted down the tube of the scope.
There are some other companies that make products equivalent to a Telrad (I think the generic term is “naked eye illuminated reticle”, or something like that), but Telrads are generally considered the best, for price and quality. Also, because they’re so common, a lot of viewing guides will include the Telrad reticle on their star diagrams.
A generic term for Telrad-like gadgets that I have heard is “red dot finder”. As the term implies, they don’t project a reticle, only a red dot, but that is already useful. I’ve wondered whether the projection of a reticle is patented by the company that makes the Telrad brand, and that this is the reason why they use dots instead to circumvent the patent; but this is just speculation on my part.
Rigel Systems makes the Quikfinder, which s a smaller, more vertical version of a Telrad that uses two circles (12 degree and 2 degrees) instead of the Telrad’s three (1/2 degree, 2 degrees, and 4 degrees). It’s nice for smaller telescopes like refractors, but it’s more prone to parallax error. Some people prefer it because the window you look through sits higher up, but ScopeStuff maks a raised base for the Telrad which solves that issue, so on a big scope like a 10" dob, the Telrad makes a lot more sense to me.