Question
I don’t believe $100/kg is even within an order of magnitude of the cost of modern carbon-fiber based materials (although I may be wrong).
Anwser
Hercules, Inc. Composite Products Group, Magna Utah 84044 1-(800)443-4237 gave me estimates in August of 1991 for graphite fiber in large quantity ranging from $20/lb for AS4 fiber (580,000 psi tensile strength) to $75/lb for their developmental IM9 fiber (920,000 psi tensile strength). Composite using AS4 fiber and an epoxy resin matrix has a compressive strength of 250,000 psi and a density of about 1.6 g/cc. I don’t have a finished price for mass-produced composite struts, but my sources in the manufacturing side of Boeing say that $100/lb is a reasonable number. >I think it would cost lots and lots more than that just for the materials, >not to mention developing the technology to actually do construction at 20 >miles of altitude, worrying about the dynamic stresses from sticking up in >the jet stream, etc., etc. You do construction at ground level and jack up the tower as you go. 1000 tons worth of hydraulic jacks can be had for a couple of thousand dollars. It is true that wind loads are the dominant force driving tower design from the ground to 20 km or so (peaking at 10 km). Even assuming peak winds of mach 1 in the jet stream, by proper design of the structure you can withstand it reasonably. The main thing is to reduce drag on the struts. Since I work for an airplane company, the solution was obvious – use airfoil shapes. Put an airfoil shaped cover on the struts, attached by ball bearings on the strut tube so it can pivot into the wind. This reduces the drag by a factor of 10 or more. Also, since we build composite aircraft structures, we are somewhat familiar with the design environment. And with the Airborne Optical Adjunct program (infrared sensors to spot incoming ballistic missiles) we have some experience mounting telescopes on top of aircraft – which is a similar environment to on top of a multi-mile tower.
Associated Edu Science Telescopes Question:What this about K2 being taller? It all depends where you are measuring from…mean sea level or distance from the nominal centre of the earth. At least that’s what I’ve been told. — Geoff. Lane. | Internet: zzas…@uts.mcc.ac.uk | Janet: zzas…@uk.ac.mcc.uts UTS Sys Admin, Manchester Computing Centre, Oxford Rd, Manchester, M13 9PL During a week’s TV I want to be entertained, bored, delighted, disgusted, made happy, saddened, enlightened, mystified, else they aren’t doing the job right.

• Anwser:Sorry Geoff, you’ve been told wrong. At least if you are claiming that K2’s peak is the furthest from the center of the Earth of any spot on the Earth. That prize goes to a high peak in Ecuador, due to the equatorial bulge of the planet. (I think it’s Chimborazo(?)). Chris Anderson Science Operations Specialist ANDER…@STSCI.EDU Science Planning & Scheduling Computer Sciences Corporation Space Telescope Science Institute
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Question
I am considering purchasing a 30 inch Obsession Telescope. Anyone have any experience with these telescopes??
Anwser
The behauvior of the 24″ Obsession we have here in Finland depends strongly on the weather. It usually works well as long as the night-time temperature is over 0 Celsius. But as Finland if between 60-70 northern degrees latitude it is not unusual to have temperatures close to -30 C in the wintertime. -10 C is enough to change to ’scope to what we call the Depression. Focusing becomes impossible. Now it work a bit better after the focuser was changed to a model without friction-based drives. Collimating the Obsession has also been quite painful as it is owned by several people around Finland and therefore the telescope travels a lot in its container. This problem will of course not arise if the telescope it situated in an observatory building. To sum up: The big Obsessions are excellent IF you are living in a warm (and dry) climate and have some experience with big telecopes. If the telecope is not within a dome wind will be a serious problem. The tube has about as much surface as a sail of a small sailingboat! Byu some good-quality 2″ eyepices and a set of 2″ narrowband filters to get the best results. Good luck!
Associated Obsession Telescopes Question: Is there anyone who owns an Obsession Dobsonian or knows something about it?

• Anwser:I don’t own one but several of my friends do. I’ve used both the 18 and 20 inch versions. And surprisingly there is a very large difference between the two: the 18 is a nice size, I have to use a ladder only quite near the zenith (though I must point out that I am 73 inches tall). The 20, OTOH, is huge, requiring a ladder most of the time. From my perspective there is thus a VERY large difference in easy of use between the two. I have not yet actually used both sizes side-by-side but from memory the images are not all the different. I do agree with David Knisely’s comments about their excellent overall quality. If I were buying another telescope today (I currently own a 12″ LX200) I would buy an 18″ Obsession. — Bill Arnett bi…@znet.com http://www.seds.org/billa/ “I know that I am mortal and the creature of a day; but when I search out the massed wheeling circles of the stars, my feet no longer touch the earth, but, side by side with Zeus himself, I take my fill of ambrosia, the food of the gods.”

Associated Obsession Telescopes Question:Obsession. Any good advice is appreciated as I may be in the market to get rid of the SCT and buy a nice dob.

• Anwser:And this might not be a bad idea. IF all you want to do is visual observing. Sure the 15″ presents a “better” image of a deep sky object–it should because of the larger aperture, offering a near 300% light gathering advantage. Just be sure you won’t be sorry you gave up the driven mount and the other niceties than C9.25 offers. I own a 12.5″ truss tube and like it very much. It’s a simple no-fuss no-muss kind of telescope that just performs. That said, I use my SCT more often because I have a wide variety of interests–imaging, etc.–in addition to visual observing. Don’t get carried away, either. In the quest for aperture you can get to the point where it gets messy: that is, your choice of vehicle is decided by your telescope. A 12-15 inch won’t cause many problems in this regard, though. Obsession is great, as is Starmaster, and several other custom dobs. You can also build one yourself if you’re handy about woodworking, etc. AstroSystems offers the Telekit, which produces a beautiful scope–in some ways the most impressive of all the truss tube. Before you decide to turn in your SCT and build or buy a truss tube dob, I’d suggest you do some long, hard thinking about your planned observing projects, etc. I’d also suggest you trot over to Willman Bell’s web site and buy Berry and Kriege’s _The Dobsonian Telescope_, which is a wonderful book, the bible of the truss tubes. Peace,
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Question
i am a newb, just bought my first light bucket, and have used it for a few nights. i feel it is not as clear as i would of suspected and was wondering if it could be something that is not right. when looking at say jupiters moons, each moon is not a dot but rather a boomerrang shaped, which one might think is from movement, but its the same with the fan on or off, and the base is sitting on a pretty serious concrete patio. i’ve collminated the telescope like 8 times, all with the same results. i am using the 1.25″ lense. i am wondering if it is a factory problem, or something else, of if this is common, and i should get use to it. if anyone has any experience or thoughts, it would be very appreciated. thanks
Anwser
When collimating faster scopes, it’s necessary to really dial it in perfectly. So when you’re collimating, you need to use a high power eyepiece combo (like around 300X or above), and once you’ve collimated it out of focus you need to collimate in-focus as well, using the faint diffraction rings around the star. The problem is that there are very few nights (at least around here in upstate NY) that are steady enough to do this. Usually you’re just getting close. If the collimation is in, then the next likely culprit is either cool-down or seeing. Make sure to give your scope a couple of hours to come to the same temp as the surrounding air. With my C8 I routinely notice improvements after 2-3 hours. With a 10, which is thicker, expect even longer cool-down times. Get the scope off of the concrete patio, too. Those things absorb heat all day and radiate it away at night, ruining seeing above them. Put the scope out in the middle of the lawn, or take it to a grassy spot in a park or out in the country. Seeing can be a real bear and can often mask decent optics. Take a look at your local clear sky clock and take a look when the forecast is for excellent seeing. If the collimation is good and your scope’s performance is still poor, start suspecting the optics. On a related note, eyepieces can also cause kidney-beaning on stars at the edge of the field. Do your jovian moon boomerangs seem to change shape from one side of the field to the other? Could be coma in the primary (which is always present to some degree in fast newtonians), or it could be a mediocre eyepiece. To get the most out of fast optical systems you need to unbelt a little for good eyepieces. You might try to get a university optics ortho on astromart. Quality is excellent and they’re not too expensive second hand. It will help you to isolate the problem, and they’re terrific planetary eyepieces for sharpness (though the field of view seems a little narrow compared to the plossls that dominate the market today). People usually jump to the conclusion that their mirror is poor, but in my experience almost all of today’s optics will perform better than seeing allows them to. In other words, the normal factor limiting performance is the sky, not the scope. So don’t worry just yet. There are some bad scopes out there, but they are pretty few and far between.

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Question
Jason Discoverer Telescope 454 Precision Astronomical Refractor Telescope 454X Maximum Magnification 910MM Focal Length 60MM Objective Lens Professional Style Equatorial Mount Hardwood Tripod with Illuminated Accessory Tray Brand New! I won it on a game show and I am willing to sell it. It is listed at $516, I will sell it for $300!
Anwser
The price is fair, but know what you’re getting before you buy! The maximum USABLE magnification on any telescope of 60mm aperture is about 130X (60 times the aperture in inches) which means that some of the eyepieces are unusable; you’ll have to buy one or two to supplement what’s supplied. The tripod and mount are marginal (“shaky” is the operative term) so don’t expect to do anything but visual observing (i.e., no photography; the aperture is too small for that anyway). All the above aside, the telescope is fine for a youth just getting interested in astronomy, or an adult who just wants to play around with a small telescope.
Associated Jason Telescope Question:Great idea, I’ll try it–can you recommend a brand that I can trust to give good performance? I’ve been meaning to upgrade to 1.25 but I’m not sure what to buy. I do have lots of catalogues and all the sites on the Internet….

• Anwser:There are many companies out there selling accessories for telescopes and now that I think about it I’m sure that I once saw an adapter that would convert your present focuser from .96″ to 1.25″ which would probably be cheaper and easier to do than to change the focuser, I don’t remember where or when I saw It but it mite be something worth checking into. If you do change focusers Meade makes one that will take both 1.25″ & 2″ eyepieces as dose JMI and probably Orion & Celestron but remember that you will probably have to drill new holes in your tube to fit them so you may want to talk to someone in a reputable telescope store before you buy because they may be able to give you some advice regarding the procedure and the scope will definitely have to be recolumated after the change. As far as new eyepieces are concerned I would stay with a known brand such as Meade, Celestron or Tele View and buy a good known design, I personally own both Meade Super Plossls and Celestron Ultimas and have had occasion to use Meade Super Wide Angles and Tele View Panoptics but the latter two are relatively expensive so you may want to stick with Plossls, Super Plossls & Ultimas. Remember that when you purchase your eyepieces that your scope dose have a theoretical upper and lower magnification limit and if you push it beyond these limits then the image is greatly degraded. The maximum magnification under good seeing conditions is about 50 x the diameter of your objective expressed in inches. The minimum magnification can be determined by the formula ml = aperture of telescope in mm / 8mm ( 8mm is the approximate size of a fully dark adapted human pupil ). To determine the magnification of a particular eyepiece with your telescope determine the focal length of your objective by multiplying the diameter of the objective by the scopes f/# ( so an 8″ f/10 scope has a focal length of 80″ ), As eyepieces have there focal length expressed in mm you should convert the focal length of your objective into mm and the divide this number by the focal length of the eyepiece and this will give you the magnification of that particular eyepiece with that scope. Geez I hope I was able to make all that stuff clear enough so that I don’t confuse the hell out everybody who hasn’t seen these formulas before, I guess that as a teacher I make a pretty good Haz waste guy! Well that’s all for now and good luck with my magnification formulas.
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Question
I am looking for building plans on a slide-top roof observatory. I just bought a home with a wonderful view of the southern sky and would like to have an enclosure to house a Mead 10″ SC telescope. I have a small lot on the side of my house that I can use it’s about 20′ by 40′ I think that should be big enough for a small observatory. I have been to the library and to book stores and have found nothing as far as detailed plans (lots of photos but no plans). If anyone has any information please let me know, I would like to get this built before winter.
Anwser
I couln’t reach you by e-mail so I’ll post this response. On alt.sci.planetary you asked about a home observatory… The magazine _Sky & Telescope_ has a regular column covering topics on home built telescopes. In that column, they frequently cover home observatories One of the neatest ideas I saw was an observatory with a regular “A” frame style roof. When one wanted to observe, the roof would split in two at the peak and slide to the sides of the shed. It was balanced with counter weights so one person could easily open and close the shutters. This month’s issue (July) of S & T talks about pre-fabricated domes that one can use on their home observatories. If you want I can dig up more specific issue numbers, volumes and pages etc. when I go home tonight…. Also a telescope building book whose name escapes me right now has an section on home telescope enclosures… Hope this helps.
Associated Home Telescope Question: Presuming the right ratio was found and they had technologies which could address the other requirements are they not still lacking in making eyepieces? They do not have transparent glass. What do they use? Natural quartz crystal and various semiprecious gemstones. Even Fluorite… Clif Ashcraft

• Anwser:The idea of rock crystal and/or other gems with a low hardness that could be easily worked sounds interesting. In theory one could even use salt if it were not for the hydroscopic qualities. How easily could they make such lenses to specifications? Could they make both convex and concave shapes? If they could, perhaps it would have been much easier to build simple refractors like Galileo’s telescope, with a simple convex and concave lens (or even an inverting image). Are there any artifacts of these rock-crystal lenses? How were they shaped or polished? I saw something on the ruins of Pompeii once that tended to seem to show that the Romans at least by that time might have had window glass for some purposes. Of course, the cathedrals of the middle middle and later middle ages would tend to indicate that window glass was used by that time. As for glass coloration, it is hard to say with regard to the impurities in various manufactures and the origin of glass coloration. Broken glass would tend to leave archeological evidence. How far back does glass for windows go, and how extensively was it used during various time periods, from ancient Egypt to the later middle ages?
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Question
Having said all that, I would go with a short tube 80 even though it costs more. I think in the long run it will be a better fit with any bigger telescopes you get. Not being able to see the rings of Saturn is a big limitation.
Anwser
Yup. The ST80 is really a better scope than either the Bushnell _or_ the Astroscans I’ve seen lately. Despite the attraction of the Bushnell/Astroscan as far as handholding/cradling in your lap, or setting up on a convenient flat surface with the base, these scopes really don’t make it. The Bushnell is ickily cheap. And the Astroscan has got worse with age, it seems. Optically, the average 80 is lighyears ahead of the Bushnell for sure. And mine outdoes the (usually non-collimated) Astroscans I’ve seen lately as well. Image brightness? Didn’t notice much difference. Frankly, the ST80 actually seemed a tad _brighter_ to me, if anything. You don’t often hear the 80 touted for high powers, but mine certainly bears higher power better than the Astroscan, allowing me to see the Great Red Spot on Jupiter, other details on Jupe and Saturn, etc. As far as the convenience of the Bushnell/Astroscan base…it doesn’t add much. How often is there a convenient surface to set one on out in the field? You’ll have to add a photo tripod that’s decently steady to the mix, and that will run up the price. And the Astroscan scopes are usable handheld only at very low powers. Nah. Forget these. Get an 80.
Associated Bushnell Voyager Telescope Question: If it’s the same as other bushnell scopes, one should turn around, face away from it and RUN LIKE HELL! That’s for sure. A friend who’s a stocker at a local supermarket was just “awarded” a Bushnell Voyager 78-9565 Refractor and the rack-and-pinion focusing assembly literally disintegrated. I couldn’t even identify the “metal” (the alleged “pot metal”)

• Anwser: Pot metal in which sense? ” An inexpensive alloy of poor quality, usually containing lead, used especially in making castings” Though none of the definitions I found look like something you’d use for a rack and pinion

Associated Bushnell Voyager Telescope Question:I am interested in the Bushnell Voyager telescope (the model which is the Edmund Scientific Astroscan 2001 clone, that is)… My question is: How are the optics for the Bushnell Astroscan Clone? Are they as good as the original by Edmund Scientific, or are they poorer or somewhat compromised? Would it be a good investment or not? I already have a refractor and a 4.5 ” Newtonian reflector; I’m just looking for a decent scope which is extremely portable. I couldn’t help but note that the Bushnell clone is about half as costly as the Astroscan, and I guess I’m wondering if it’s only half as good, too.

• Anwser:I’d say “about equal.” I haven’t had the chance to look through a Bushnell yet, but based on what I’ve heard the scope includes a spherical mirror. It does however have collimation adjustments for the primary. This would probably make it pretty competitive with the average out-of-collimation Astroscan. Actually, I’d suggest you look at an 80mm F5 refractor like the Orion Short Tube or Celestron WA80 instead. These are small and portable–though you will have to provide at least a camera tripod as a mount unless you choose Celestron’s GEM mount version. But the bottom line is that these little suckers will beat most Astroscans I’ve seen hands down. Images–stars and planets–are much sharper and, believe it or not, based on comparisons I’ve made, the images in the little refractor actually seem brighter.
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Question
Hi, in the ARRL Microwave Experimenters Manual telescope brass tubing is recommended for making cavity and interdigital filters. According to the book this tubing can be found in every hobby shop. I haven’t seen something like this here. What is this tubing intended for originally? And what is it? Just tubes with different diameter? Or really sets of telescopic tubes already slotted?
Anwser
Hello– Next to a small bin filled with chunks of balsa and basswood, our local hobby shop features a small display of structural plastic and metal strips and assorted shapes; the brass tubing comes in various sizes that do indeed telescope together– the tubes are solid brass. You might want to do an internet search for “hobby supplies”– that may turn up some leads to suppliers or even the vendor of the display. The brass tubing sells for anywhere from $.50 to $1/50 per one-foot section.
Associated Telescope Brass Question: On Tue, 03 Jul 2001 22:58:43 GMT, Acme Optics acmeopt…@earthlink.net> wrote: “Michael G. Tokman” wrote: Greetings and Salutations, We are happy to offer ORIGINAL 1880s NAUTICAL BRASS TELESCOPE; LONDON for auction on eBay. Please view it at: http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1442472832 Thank you in advance. Michael. Be careful everyone. A lot of that 1880 brass stuff is actually 1990 brass stuff from the far east. You would be lucky if you get a 1990 falsifikate, better optics, think of it

• Anwser:It isn’t a given that the optics will be better. The knock-offs probably come from the same places those dreadful “telescopes” sold in dept stores come from. For what a optically good functional real antique brass telescope is likely to cost, one can buy modern all-metal (and glass of course) telescopes with essentially perfect optical characteristics. TeleVue makes my objects of desire. www.televue.com So, it all comes down to intent: Do you want a beautiful antique, or do you want beautiful optics? I can understand both desires.

Associated Telescope Brass Question: I want to try making a finder scope for my telescope. I have a cheap set of binoculars from a flea market. I intend to use only the main lens and eyepiece, not the prisms. I figure on turning a mounting ring for the lens and an eyepiece mount. It looks like I will have to use sheet brass for the body as I have not been able to find thin enough 2″ tubing. Anyone done something similar? What thickness of brass should I try? Any tricks to soldering the seam?

• Anwser:I wouldn’t give up on finding the tubing, but if you want it’s not at all hard to roll one from sheet brass. It helps a lot if you have a mandrel that will be a tight fit inside and able to take brazing heat, but it’s not absolutely necessary. I would try .020 sheet – I usually use .014 for musical instruments, but you might want extra strength. If you need to cut threads in it, I would recommend inserting a ring an machining that, or you will have to use much thicker sheet. Anyway, you want to roll it around the mandrel and burnish the edges to meet in a butt joint. Bind it in place with iron wire. Flux with borax and braze/solder with 55%Ag/35%Cu/10%Zn or a similar high-silver alloy, using hot propane or if you have it Acetylene/Air. I don’t think you would need anything more than a butt joint – I only bother with an overlapping toothed joint on sections that are going to see significant cold working. My instrument web pages (in sig line) talk about the process…
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Question
Maybe I’m missing something, but if the telescope (or cooker) is mounted on an axis parallel to the equator, it seems like all the tracker has to do is turn the telescope (or cooker) at (360/24) = 15 degs per hour in the opposite direction to the way the earth is rotating?
Anwser
The trouble is that, except at the poles, the axis is not vertical. If your cooker is attached to a sloping axle which rotates, the cooker will be slowly tipped over until the food falls out. Generally, it’s a better idea to keep the cooker stationary, relative to the earth, and arrange some sort of reflector that moves so as to keep reflecting sunlight onto the cooker from the correct direction. A heliostat, in other words.
Associated Sun Telescope Question: In order to avoid misunderstandings: If you are using a telescope, the film MUST be placed in front of the telescope. NOT between eye and eyepiece. Usage as “window” or solar goggles is only for observation with the bare eye. BTW: Don’t miss to cover your finder when observing the sun by telescope. An uncovered finder may focus the sun on your head!

• Anwser: An uncovered finder can be a useful way of finding the Sun, which can be an extremely “elusive” object to actually get into the telescope’s field of view! My normal method of finding the Sun is to use the scope’s shadow to get it approximately in the field (by moving the scope until the shadow of the tube is minimized), and then to place my hand a few inches behind the finder’s eyepiece and move the scope until I see an image of the Sun on my hand. I can then centre the image in the finder’s field, which will place it into the scope’s field of view. Having done that, I obviously cap the finder. Regard,

Associated Sun Telescope Question:Okay, I’m going to come out really idiotic-looking here, but I figure anything I learn now will prevent patrons of mine from doing damage to themselves later, especially with the annular eclipse coming in May. We have all seen the Mylar balloons, and have all heard of Mylar filters for telescopes. Is the Mylar used in the balloons as thick as the filters, or are they completely different animals. I want to keep someone from cutting one of these deflated balloons and using it for a filter to view the sun.

• Anwser: Nothing idiotic about it! A little learning is a dangerous thing, and nothing is so boneheaded that someone won’t try it. The Mylar could be the very same stuff in both applications, but the COATING is what does the work, not the Mylar. Tell them, for God’s sake don’t use a cut-up balloon! The balloon might appear nearly opaque to visible light but will almost certainly pass dangerous amounts of UV or infrared. Ask them whether the risk of permanent eye damage or blindness is worth saving a few dollars.

Associated Sun Telescope Question: No matter where the sun is in the sky, and no matter whether it’s in eclipse or not (same question, basically — both situations reduce the amount of solar radiation reaching the telescope, but not enough), IT IS *N*O*T* SAFE TO PUT YOUR EYE TO THE EYEPIECE WHEN THE TELESCOPE IS POINTED AT THE SUN.

• Anwser: You definitely want to be extremely cautious when risking your eyesight, but I have viewed a sunset with binoculars. When I was on the Gulf side of Florida, I was watching a boat on the horizon which went near the setting sun. I noticed as I was getting nearer the sun, that the sun’s rays were so attenuated that it was comfortable to look at in the binoculars. At this point, the sun had already started to dip below the horizon, which was the sea. It was cool because you could see the silouette of the waves on the horizon against the sun (I calculated that the waves were three or four miles away). However, at other locations, the sunset will likely occur higher in the sky (over trees, hills, or buildings) and therefore be attenuated less, so USE CAUTION! By the way, the company I work for makes some equipment for measuring electrical stuff. Accessories for one of the products includes a fixture for measuring very small capacitors, and it has an attached magnifying glass to help position them. There is a warning in the manual not to view the sun through the magnifying glass. How stupid do they think people are? Do they also need a warning telling someone not to drop the equipment on his foot?
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Question
A great many telescopes are easy to carry. My old 3-inch alt-az Newtonian certainly was. For those of us who travel extensively, sometimes to places with VERY dark skies, the high-quality optics, stability, integration and ease of use make the Questar the best choice.
Anwser
If you specify your needs carefully enough you might be able to make almost ANY telescope appear to be the best choice. For purely visual use at distant dark sky locations a somewhat larger SCT, Mak or a Newtonian RFT would be my choice. OTOH a Questar would be handy for photographing a solar eclipse and for taking astrophotos of showpiece objects on a trip to the Southern Hemisphere, but even so, there are other astrophoto options to consider. The OP didn’t say whether he recently inherited a large fortune, landed a high-paying job, or just won a few thousand in a lottery. Nor did he specify whether he was interested in the 3.5 or the 7.
Associated Questar Telescopes Question: I am pondering the purchase of a telescope. An astronomy teacher informed me that his scope of choice was Questar, the three-inch in particular. I’ve looked around but cannot find one. Can anyone give me information (I live in the Denver area.) Expensive, expensive, expensive, small aperture, but views of the planets are nice, but not as crisp as a good refractor. I’d stay away from them if you’re a first time buyer, IMHO.

• Anwser: Au contrare. Ask someone who’s owned two. My Questar Duplex has contrast equal to any refractor I’ve looked through, and better color correction than any I’ve ever used. Even my TeleVue Genesis, nominally apochromatic, showed some secondary color at high margnification. You’ll never see that with a Questar. However…a Questar isn’t for everyone. It’s very expensive- $3200 for a 3.5″ scope on a table-yop powered EQ mount. It’s only for those who want the ultimate combination of portability and exquisite optics, and for whom money isn’t an issue. Nothing else combines so much function and quality in such a small package. A lot of folks who look through a Questar are disappointed. It’s not a super deep sky scope under light polluted skies, and the absolute maximum magnification you can reasonably get is around 220x. But the contrast and resolution is superb. At a recent party a friend was showing me how much more impressive M3 looked in his C11 at 400x than it did in my Questar at 180x- but he was amazed that the Ring in Lyra didn’t look much more impressive in his scope than in mine. And mine sets up quicker, too. For a third the price you can get a Celestron C5+ with a better mount and more aperture in a somewhat larger package. The optics aren’t in the same class, but it’s a heck of a nice compromise.

Associated Questar Telescopes Question: . . . . . . . . . . It may be engineeried very well and it may have initial appeal but all the engineering in the world can’t make up for a small aperture.

• Anwser: That is true. However, if you are going to take images, all the aperture in the world can’t make up for a mount that jerks and bounces around like some do. Questar telescopes have probably the finest mounts available as standard equipment on a packaged telescope, unless you find a package that uses something like a Losmandy mount. Then you are up in the same price range with Questar.
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Question
Hi Folks, I don’t usually hang out here but I believe most of you from experience could answer a couple questions for me. 1) My son would like to build a homemade telescope or microscope. Since he hasn’t made up his mind yet I thought I would go directly to the experts in optics.
Anwser
How old is your son? I strongly recommend that you give it a try. Do NOT go into it with the idea of saving money or producing something similar to what you would get commercially. But it is enormously satisfying and very educational. Even if it’s just a 3x Galilean telescope made out of a paper-towel tube, the excitement of doing it yourself is incredible. I was never a serious amateur telescope builder–I never ground my own mirror, or built a high quality telescope. But the hours I spent hacking around with cheap Edmund lenses and prisms were just golden. I think my favorite project was building a “pseudoscope”–just an arrangement of mirrors anchored to a chunk of plywood–that worked sort of like a pair of periscopes to invert the position of the left and right eye so you saw everything in _reverse_ depth.
Associated Question:2) “If” it’s not too difficult to locate all the components do you still get wipped by the larger companies.

• Anwser:Maybe. If, on the other hand, you can find a photographer who’s throwing away equipment, if you got, say, a nice old 300 mm f/5.6 telephoto lens, and maybe, say, a microscope eyepiece from somewhere, you could make a pretty good telescope… Think of it this way. You’re trying to build, depending on your dedication and skill level, the optical equivalent of a go-kart, or maybe just a soapbox derby car, or maybe just a little cub scout pinewood derby model car. Yes, you’ll get more for your money at the used car dealer. But that’s not really the point.

Associated Question:3) Last question. Would this be too complicated for us to build especially since neither one of us is knowledgable in optics. 4) Sorry, one more question. is there an FAQ for this group that wpuld list suppliers of the various components required.

• Anwser: Well, there’s always Edmund, not as good as they used to be, 609 573-6250, Edmund Scientific Company, 101 East Gloucester Pike, Barrington, NJ 08007-1380, USA. The library should have books on amateur telescope making, the kind where you grind your own mirror… actually you can learn a hell of a lot by buying a makeup or shaving mirror and trying to make a Newtonian reflector out of one of those! See if anyone is discarding any old optical junk you can take apart. Old single lens reflex cameras are great, particularly if you can find a telephoto lens–take one of those apart and just see how many lenses are in it. The mechanical details are mostly this: what are the best ways you can figure out to build black tubes that are mechanically rigid, and anchor lenses and prisms in them? –

Associated Question:I want to build my own Reflector Telescope. Where is a good source for the optics? Also, if anybody knows a good source for the “plans” of other homemade scopes I would be grateful.

• Anwser: You don’t say where you are — if you are in the USA, check out Bob Lombardi’s resource page; if you are in the UK check out mine. Youcould also look at the ATM FAQ. All these are available via the URL below.
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