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Purchasing a telescope, New or Used... THAT is the question!

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                                                Purchasing a Telescope - New or Used, That is the question!


In the summer of 2021, I purchased my first telescope, new, from a major brand telescope company.  I probably spent from about January until June 2021 looking at various online bits about what telescopes offer the best (fill in your subject here).  I thought I knew what I wanted from a telescope and what I wanted to observe.  I made my purchases and waited for my new, shiny galaxy gazing cannon to arrive.  In the past two years I have upgraded or replaced:  the focuser, the spotter scope from 40mm to 50mm with a diagonal; the tripod equatorial style mount replaced with a Dobsonian; added a laser spotter and a cooling fan.  See what all my research did for me?  I didn’t know what I didn’t know about what I really did need (or want).

Are you new to astronomy?  Trying to figure out what you want or need to start or further your journey into observing the heavens?  Wanting to add a specialized component to your astronomy tool kit?  Are you working with a limited budget?  Buy used! Unlike automobiles, telescopes can remain in like-new condition for years if properly cared for. You can pick up a quality second-hand scope for much less than its original price.  With the money you saved purchasing, you can modify the telescope to your personal needs.

Experienced backyard astronomers routinely purchase used telescopes and telescope equipment. Over the years, most everyone involved in astronomy has picked up a treasure trove of used astronomical equipment.  (Read to the bottom for a few examples) Here are a few guidelines for beginners purchasing a second-hand telescope.

  1. Consult more experienced astronomers.

For the individual who doesn’t know a refractor from a reflector, this is absolutely essential … contact a local astronomy club.  Many members have a different telescope (or scopes) that meet what they want to observe and how they want to observe.  Ask the questions, they will be glad to serve as your telescope-buying mentor.  Just remember, your wants and needs may not align with your mentors, so any advice offered needs to be considered as just that, advice.  You’re the one who will be using the telescope.  Get what you want.  Never feel pressured into getting a specific scope or component.

  1. Decide how much you want to spend.

We all have a budget.  A good price range is between $100 and $300. In general, anything going for under $100 can be “questionable” with iffy optics and wobbly mounts.  I have personally purchased two different telescopes online on the cheap, I paid $28.00 for one and $44.00 for the other (shipped)!  One is used exclusively for lunar observing and the other for solar observing. I build a solar filter that neatly attaches and offers some amazing views of sunspots.  Both have some limitations, but work well for what I use them for.  I actually saw a twin of these telescopes for sale online, new, $270.00 plus shipping.

Often, a used telescope has been well treated and upgraded to some degree for the previous users needs.  No telling what the previous owners needs were, but with time and experience, you will know what questions to ask and what to look for before purchasing a used telescope.  On the other hand, telescopes exceeding $500 are typically more complex.  Such as catadioptric telescopes (look that term up) and larger-aperture refractors and reflectors.  These telescopes might be too much for the novice to handle. 

  1. Know the type of telescope you want. That last sentence is much easier said than done. Step one…. Start learning! 

The ideal beginner’s telescope is easy to set up and take down, transportable to remote locations, user-friendly, and suitable for viewing a variety of celestial objects. In other words, an instrument you’ll use again and again. Look for a 70, 80 or 90mm refractor or a 6- or 8-inch reflector.  I wouldn’t recommend a refactor smaller than 70mm, as a nice pair of binoculars would offer a similar (or better) viewing experience.  The smallest reflector telescope I found was a 76mm (3 inch) and it was very basic in all its elements.  More common are 102mm (4 inch), 114mm (4.5 inch), 127mm (5 inch) and larger.  A reflector style telescope does have a few additional learning curve elements to learn/master.  Such as collimation, possibly polar alignment, etc.

Keep it simple and forget any electronic gadgetry — at least for now. Let your first scope simply take you on a visual tour of the universe. If it gets you hooked on backyard astronomy, you can move on to more advanced activities like Astro-imaging with your next scope.

  1. Search the classified ads

Armed with an idea of what you want in a telescope, it’s time to begin your search. Occasionally, you’ll come across a hidden gem of a telescope at a yard sale, pawn shop, donation center or in a newspaper classified ad.  Craigslist and eBay are other online shopping options, but may contain the occasional lemon.  A source for better quality items is Cloudy Nights Classified, which offers equipment solely for the amateur astronomer and contain ads put out by reputable and knowledgeable sellers.

Whatever the source, be especially wary of any used telescope whose chief selling point is a high magnification — a clear sign the seller is trying to distract you from seeing faults and hoping you will be drawn in by the magnification illusion. The general rule is 50x per inch of aperture. Any higher and you risk dim, fuzzy images. 

Another way to ensure a quality used scope: Pick a manufacturer with a good reputation.  Since this is your first telescope, and your still shopping, ensure you are aware of what is being offered when you do purchase new. Double check with the listing and/or seller that you’re getting an entire package — optical assembly (tube, finder, focuser, and optics), mount, and at least one eyepiece. The user’s manual is a big plus, but, if missing, can probably be downloaded off the internet.  Knowing what is and is not provided when you purchase is key.  Most every missing component is available separately.

  1. Know the cost of the telescope when purchased new.

Once you’ve zeroed in on a particular telescope, and before you contact the seller, make an online search of the manufacturer and model to determine what it costs when new and what accessories came with it. A fair asking price is 50-75 percent of the original cost. That can fluctuate depending on the condition of the item. If there are missing accessories, it should cost less. If it’s literally in just-purchased, still in the box condition, then it will cost more. Don’t get emotional when purchasing, understand that patience often means less expensive. 

In many cases, the telescope is an excess item or the telescope belonged to an older family member who has since passed away.  In either case, the telescope is available for you to enjoy.

  1. If possible, buy locally.

Buying locally allows you to acquire your telescope today and use it immediately (weather permitting). More importantly, you can inspect the scope in person to ensure that it’s been “used” and not “abused.” 

Your inspection should start with a general look-over. A telescope doesn’t have to be cosmetically perfect but be wary if the tube has any major dents or rust spots.  In most cases these blemishes indicate less than perfect storage but are often a means for getting a better deal.  Except for damage to a mirror or glass lenses, most everything else can be repaired or replaced.

Check the eyepiece focuser to be sure it runs smoothly.  If the focuser is too tight or loose an adjustment may correct this issue.  You may find that some simple cleaning and some lubricant is the answer. 

Depending on how the focuser is designed, the disassembly, cleaning, lubrication, reassembly and adjustment takes but a few minutes.  You would be amazed how many online tutorials are available for assistance.  Also, see what size eyepieces the focuser will accept.  0.965”, 1.25”, and 2.00”.  If the focuser uses the 0.965”, adapters are available to use the more common 1.25” eyepieces.  Be aware though adding an adapter may change the focal length of the focuser more than the eyepiece can adjust for.

Then peek through the finder or spotter scope. The optical type should provide a clear and sharp view and the crosshairs (not always included) should be intact. A finder should display a red dot or an illuminated circle when turned on.   Batteries are often the culprit when the red dots do not work.  Be careful how you remove the battery cover.  At times the rheostat (red dot intensity adjustment knob) may have some corrosion causing dead spots. Using WD-40 or similar product can help remove the corrosion or dead spots. Or you may find you just want to use a different design than was provided.  Again, personalize so you are more inclined to use your new telescope.

If the telescope is a refractor, inspect the objective (bit end) lens. A little dust is OK, but scratches and chips are a deal-killer.  I totally recommend you walk away if the objective is damaged in any way. The same goes for the objective and secondary mirrors on a reflector. Check for reflectivity. A hazy or blotchy mirror is not a disqualifier, but I recommend you keep looking.  Remember this is your first telescope.  If it was your second or third (or moreth) my advice might be different. 

The mount should be solid while still operating smoothly.  With the telescope completely assembled, gently tap the tube to see if the scope wobbles back and forth. Less wobble is best. A scope with an alt-azimuth type mount should point up and down (altitude) and side-to-side (azimuth) smoothly.  Again, it may take no more than tightening all the visible fasteners to remove wobble.  OR, the mount might just have too many points of movement to make the mount desirable.

You can find out a bit about your prospective purchase by asking the seller three questions. Why are you selling the scope? What do you like about it? What don’t you don’t like about it? 

Once you’ve kicked the tires, it’s time for a test drive. Ideally, you’ll want a clear evening when you can test scope and eyepieces on celestial objects. If that’s not possible you can still check it, however. In daytime, test it on a few distant objects. On a cloudy night, try far-off streetlights.

  1. If you purchase and cannot physically check out the telescope, contact the seller

Purchasing online does add a level of risk. Question, can the telescope be returned if you are not satisfied? Can you contact the seller and ask your questions. Start with the ones outlined in the previous section. If the seller’s ad didn’t include images of the telescope, ask for a few — if necessary, specify that you want pictures of certain aspects of the scope.  Use a credit card (not debit) to help protect your online purchase.

Consider the long-distance purchase of a telescope with caution. You’ll incur the extra expense of crating and shipping by the seller — usually included in the price if shipping is “free” — and several days (or weeks!) until the scope reaches your doorstep. You also run the risk of damage while it’s en route.  The advantage of purchasing online, the prices are often much lower.  Consider what has a higher concern for you… purchase price or ability to buy and drive?

Whether you’re a novice backyard astronomer looking for your first telescope or a seasoned amateur astronomer seeking a second, third  (or moreth) instrument, you can save big bucks by purchasing second hand. Follow this advice, and you’ll wind up with a telescope that paves the way to a lifetime of astronomical adventure.


HERE is a Post Script for the benefit if those who read to the bottom.  I personally know of 2 great transactions that happened in our Club.  The first was a gently used 10 inch reflector on a dob mount (plus some accessories) new for about $800-900 plus shipping acquired for $300 and a 3 hour round trip drive.  The second was an 18 inch, f4.5, reflector on a dob mount, with a feather touch focuser new for about $9000 plus shipping acquired for a round trip north of Atlanta GA.  The scope was free to a good home.  Bargains are available, these are just two (maybe extreme) examples of what might be found.