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Stargazing Planning to buy a first telescope?

  1. Mar 30, 2010 #1

    turbo

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    We often have questions about what telescope an aspiring amateur astronomer should buy. The "correct" answer can be elusive and is highly dependent on a lot of variables, including the expectations of the questioner, budget, storage capacity, available transport, etc. Rather than type all this advice over and over, I'd like to offer this post in the hopes that it can be made "sticky" so others can add to it, and it can remain near the top of the astronomy forum.

    Before you spend a dime, find a local amateur astronomy club, and see if you can attend meetings as a guest. Get there early and mingle. Let the members know that you are interested in pursuing astronomy, and that you are open for suggestions about what kind of gear might be appropriate for you. You can get valuable guidance that way. Next, arrange to attend the club's next star-party. Often they are open to the public as an outreach effort. Again, show up early. This is valuable for you in many ways. You will get to see what kind of transport requirements are involved in owning and operating a range of telescopes and mounts. You will also get insight into the simplicity/complexity of setting up various types of gear. Also, you'll get to observe through a variety of instruments so you can get an idea of their strengths and weaknesses. Observing will also help dispel high expectations brought on by agressive marketing by telescope vendors. The nice color images of nebulae in the ads are a come-on. You'll see varying shades of (mostly) greenish-gray at best. You can see colors in stars and planets through modest amateur scopes, but not in galaxies or nebulae. The pretty pictures in the ads are made by skilled astrophotographers. Your eyes cannot integrate photons over long periods of time like cameras can, so you will not see colors in dim objects.

    Another great advantage to hooking up with local amateurs is that lots of observers are gear-hounds, and they may have scopes in their closets that are gathering dust while they use their newer gear. You could get a great deal on a used telescope, and best of all, you'll get to try it out before you buy it.

    Now, do you really need a telescope? Even a modest instrument can bring you a lot of enjoyment. If you buy a nice pair of binoculars and a decent set of charts, you can see a lot of objects, and learn your way around the night sky. My advice is to get a pair of no-frills binoculars from a high-end optics company. While you won't get the options available on their pricy models, you'll get binoculars made with the know-how and quality-control of the high-end company, so the quality of their basic instruments is often impressive. It's a bit of a cliche, but 7x50 binoculars (7 power with 50mm objectives) are great for general use. They are with me during every observing session and are the go-to instrument for quick peeks.

    If you still decide that you do need a telescope, what are your options? The best bang for the buck comes in the form of alt-azimuth mounted Newtonian telescopes. You can get pretty impressive aperture for reasonable money. Newtonians on German equatorial mounts are no better optically in general, but cost more because of the extra expense of producing a mount that can be polar-aligned and driven to compensate for the rotation of the Earth without field rotation. Another choice, though generally more expensive still is one of a wide range of catadioptric telescopes. These are relatively compact telescopes with folded light-paths. These can be made fairly portable (compared to Newtonians of similar aperture) but are generally slower (longer focal lengths) which give images that are not as bright as those of the (usually) faster Newtonians. At the higher-cost end of the field are the refractors. Not the cheap department-store refractors, but high-quality instruments often made with exotic high-dispersion lens materials. Such refractors can deliver very high-contrast views in part because there are no central obstructions in the light path, unlike the Newtonians with their diagonal mirrors or catadioptrics with their central secondary mirrors. Each type of telescope has strengths and weaknesses.

    Next, learn a bit about optics, if you can. Many inexpensive Newtonian telescopes hit a price/aperture price point by compromising on mirror quality. This means that you will be paying for spherically-figured primary mirrors and not the more difficult-to-figure parabolic mirrors. Google on "spherical abberation" to see why you might want to consider paying a bit more for better optics.

    To add to your confusion, there is a dizzying array of mounts and automation. It is possible to buy simple alt-azimuth mounted Dobsonians equipped with encoders that can help you find objects. Many German equatorial mounts and fork mounts come equipped with encoders and computers, some loaded with tens of thousands of objects. These "aids" can be very attractive to a newcomer to the field, but in my opinion, it is not worth the money to get trapped into the automation. When the encoders fail, the computers fail or get corrupted, how will the purchaser get service? Pack up a delicate scope, ship it somewhere for service, and hope the manufacturer has a stock of the failed parts and can fix the instrument? I may be anachronistic, but my advice is to buy an optical tube assembly that is suitable for your purposes on a mount that is no more complex nor automated than absolutely required. I have a 6" apochromatic refractor on a German equatorial mount. The mount has electric drives on both the right ascension and declination drives. Top-quality optics on a really basic mount. I don't need automation and computerized slewing to find objects, because I learned my way around the night sky with charts and star-hopping. When someone asks "what's that star?" I have a catalogue of them in my brain - no computer required.

    OK, got a telescope? Next, you'll want to consider accessories. Please do not buy an assortment of eyepieces right away. Use your association (hopefully membership) with the astronomy club to figure out what eyepieces work well with your telescope. Most amateurs are pretty stoked about their favorite EPs, and will pop them into the focuser of your 'scope to show you what the buzz is about. If you're a beginner on a budget, please be aware that some well-heeled members may have some exotic EPs that cost more than your entire 'scope, with accessories, so be polite if they are a bit hesitant to hand them all around. I have a well-corrected f:8 refractor and it performs well with Plossels, and I have only one Nagler. People with high-end short focal-length reflectors often gravitate to very expensive exotic EPs to get top performance, negating some of the economic benefit that can come with sticking with big reflectors. Find out what works well with your telescope, and let that experience guide your eyepiece-shopping. Next, you'll need to consider EP focal lengths. You WILL want to buy a Barlow lens to let you use your longer EPs (with better field of view and eye-relief) for high-magnification observing. Before you pick a Barlow, consider what EP focal lengths you might want to use. If you have a 10mm and a 20mm EP, and you buy a 2x Barlow, you'll end up with only one extra unduplicated magnification. Stagger the focal lengths of your (planned) EP upgrades to give you a good spread of magnifications. Remember that you should spend money wisely on a high-quality Barlow, because you'll use that critter more than you think, and it will allow you to get a lot more flexibility out of your rig, if you plan properly. Consider Barlows of 2x, 2.5x, 3x at a minimum and spread-sheet the resultant magnifications with EPs that you might have on your wish-list. You can waste a of money for little effect if you don't plan.

    Good luck, no matter how you proceed.
     
    Last edited: Mar 31, 2010
  2. jcsd
  3. Jan 13, 2015 #2
    Wow! Thanks for the great post. I only recently started thinking about astronomy. Binoculars are great, but I have trouble keeping my arms steady enough to get a good look at anything. Any good ways to keep binoculars steady?
     
  4. Jan 13, 2015 #3

    DaveC426913

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    Tripod? Or even monopod.

    Really cheap ones can go for < $30, but you get what you pay for.

    I'll bet if you ask around your fam & friends, someone will have an old tripod they don't use anymore.
     
  5. Jan 13, 2015 #4

    DHF

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    most tripods have a hook on the bottom, you can by small sandbags from any video or photography shop like BHvideo.com
    just mount the sandbag on the hook and it will increase the tripod's stability and keep your binoculars extra steady. Just make sure the Binoculars you have come with a screw mount so you can attach them to a tripod.
     
    Last edited: Jan 13, 2015
  6. Jan 13, 2015 #5

    DHF

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    EDIT to my last post: Porters.com is aparently out of business, As you can see, I shop at B&H a lot more :)
     
  7. Feb 20, 2015 #6

    CalcNerd

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    I have a moderately priced Newtonian that I bought at a steep discount (maybe because it didn't have the auto tracking motors and other high end toys, but still costs some bucks) that I bought to replace a much lower end Newtonian that I had earlier. And it magnification and quality are really good. And I sometimes take it out and set it up. I'm glad I have it. But 90% of the time, I use binoculars. Aside from viewing the Jupiter and Saturn, I get no other real value out of it. If I use my Barlow adapter and lens to get the supposed 250 X magnification, I am constantly adjusting as the object is running out of my field of view. That is the one nice thing about buying a unit with a tracking motor. But that would require even more effort to set up. I am a 5-15 minute observer. I don't attend all night (or even a couple hours) events. Hence the Good pair of binoculars.

    I might even get enough enjoyment out of a spotting scope of 50-60X (I don't have one, but I rarely use my telescope above these ranges either, due to keeping the object in my field of view). Very simple, point and look. Primitive, down and dirty. But then I don't hang out with the amateur astronomer crowd. You really might enjoy that.

    About binoculars. Money doesn't always buy the best set of glasses. I have several pair, my most expensive are actually my poorest for night viewing. It is a high end name brand 7-21X50 variable magnification set (I think Bausch, but I don't use them enough to even remember). I couldn't pass them up at 50% off. They're ok, but color is dulled out (made for the deer hunter or possibly winter viewing during the day on snow, which might explain the less that stellar performance??). My best set is a modest 10X50 (some cheap set that I pick up and marveled at how clear the image was) and my most used is a 7X40 due to its much lighter weight and good optics. The 7X40 was my first set and wasn't expensive but a good brand name that I still use. The reason I have a few sets of glasses is so I can share with my guests if anyone wants to join me (once in a while the wife, but she would rather see something in the big telescope, looks and is almost always disappointed aside from Jupiter and Saturn).

    So my advice isn't as an enthusiast but a casual user.
     
  8. Feb 20, 2015 #7

    Drakkith

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    One thing to note here. A spherical mirror is just fine for either small apertures or long focal ratios. For an 8-inch aperture, the f-ratio needs to be about f/12 in order to be diffraction limited with a spherical mirror. Anything faster than f/12 with an 8-inch aperture will not be diffraction limited. For smaller apertures you can move to a faster f-ratio and still be diffraction limited with a spherical mirror since the airy disk increases in size with decreasing aperture.
     
  9. Feb 22, 2015 #8

    wabbit

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    Agreed, but 8" f/12 is a bit of a beast (and a specialty item, not found so easily I think), and decent parabolic mirrors are really affordable esp. Chinese ones. Good or even great starter scopes like small (say 6"f/8) dobsonians are available for $300 or so.
     
    Last edited: Feb 22, 2015
  10. Feb 22, 2015 #9

    Drakkith

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    Certainly. Newts are cheap to buy at almost any aperture.
     
  11. Feb 22, 2015 #10

    davenn

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    and specially if they are Dobo mounts :smile:
     
  12. Feb 26, 2015 #11
    Hello, nice thread for beginners.
    Can you tell me how are these for beginners:
    http://www.telescope.com/Orion-SpaceProbe-130-EQ-Reflector-Telescope/p/9851.uts?keyword=spaceprobe 130

    http://www.telescope.com/Celestron-SkyMaster-20x80-Binoculars/p/9117.uts?keyword=20x80

    http://www.telescope.com/catalog/se...&keyword=astroview+90&refinementValueIds=4508
     
    Last edited by a moderator: Feb 26, 2015
  13. Feb 26, 2015 #12

    turbo

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    I have not had the opportunity to observe through any of those instruments, nor try out the mounts. Orion is quite a popular company, so if you join a local club, you may get to try some of these instruments and compare them to others. That is the best way to make your choice before you spend a dime. Good luck to you.
     
  14. Feb 26, 2015 #13

    PAllen

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    Last edited by a moderator: May 7, 2017
  15. Feb 27, 2015 #14

    jim hardy

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    My first telescope was a cheap department store 10X to 30X 1 inch zoom handheld with a tripod mount.
    With it on my camera tripod i stumbled across Saturn. It only looked like a black-eyed pea , but even that was thrilling.

    So i took next step and ordered a Celestron "Comet Catcher."
    It is a small Schmitt-Newtonian , not very expensive .
    Using just a camera tripod i had a lot of fun with it.
    It did a great job on last visit of Halley's Comet before the tail fizzled out .
    http://www.telescopebluebook.com/other/celestron.htm [Broken]
    http://www.telescopebluebook.com/other/cometcatch.jpg [Broken]
    I never progressed beyond that little beginner's scope. Still use it.
    The Schmitt lens at end is nice because it keeps dust off the main mirror.
    It'd make a great finder for a serious telescope.

    Dad's 70th birthday was coming up. Retirement getting tedious, he was tiring of making birdhouses for the neighbors..
    He'd wanted a telescope since he was a kid so i ordered him an 8 inch Meade mirror and mounts.
    We built a redwood tube for it. It became the darling of local astronomy club.

    Advice given above regarding a hookup with local enthusiasts is most excellent. Do-It-Yourselfer's are always eager to help out.
    The guys at Southern Cross club showed us how to improve our mirror mounting scheme
    and how to make an equatorial mount from plumbing fittings.

    I found Petersen's Field Guide to the Stars and Planets a pretty good starter-out book.

    old jim
     
    Last edited by a moderator: May 7, 2017
  16. Oct 21, 2015 #15
    My first telescope and the only one I have and ever bought till date is the celestron firstscope.its a 76 mm dubsonian type reflecting telescope.it is pretty amazing actually.the moon looks awesome through it and you can see Jupiter too.I absolutely love it.I am looking forward to buy an advanced telescope than it but I think that firstscope is a perfect beginners telescope.
     
  17. Oct 26, 2015 #16

    Chronos

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    The best scope for you is tne one you enjoy using. Sounds like a success on that point. Beyond that you must decide what will please you in the future. Don't worry about getting down to magnitude 20. Eyepieces are your best friend. A good eyepiece makes a scope your slave, not master- and they are aperature insensitive. The best views for any aperature size comes from high quality low mag eyepieces.
     
  18. Oct 27, 2015 #17
    So, in your opinion is the Orion Funscope fine?
     
  19. Oct 27, 2015 #18
    The funscope is similar to my telescope(celestron firstscope).there is no difference between them except the company.in my opinion it is perfect for an amatuer.I myself am yet learning.and firstscope seems to be a decent scope to start with and so is funscope.
     
  20. Oct 27, 2015 #19
    What sort of objects have you seen?
     
  21. Oct 27, 2015 #20
    Moons crater,Jupiter,Saturn,pieldes and a globular star cluster.
     
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