Telescope Reviews, Page 1

By Ed Ting
Updated 4/24/00


Introduction
One day, about twenty years ago, my high school Physics teacher, perhaps sensing my innate boredom and restlessness, gave me a mounted 60 mm achromatic lens to play with after class. Little did he know what he was about to start. I got the lens home, and, not knowing much about optics, I began to play with it. After cannibalizing my old Milben microscope set, I discovered that I could magnify images with the little 1/2" diameter Ramsden eyepieces. I was taken aback by the quality of the images; the achromat was far better than the magnifying glasses I once used when trying to build a previous telescope. That little achromat/Ramsden combination, mounted in a cardboard tube, and rigged on a primitive mount, was my first "real" telescope, one which gave me so much pleasure that I remember to this day. With it, I saw the Pleiades, the Hyades (I could just about fit them all in the FOV), the Orion Nebula, and so many other sights. Pretty soon, I got the urge to buy a "real" telescope. I took a job flipping burgers to save up the money to buy one. At that time, there weren't many options available to amateurs on a budget. Celestron was most prominent, but there was this young, "upstart" company named Meade, whose literature caught had my fancy. I ordered one. And so I became an amateur astronomer. Such began my fascination with astronomy and telescopes. Since then, I've had the pleasure to own and use several instruments. Below you will find reviews of some of them. I have also commented on equipment owned by others but which I feel qualified to comment upon, having spent enough time with them. Prices given are list prices at time of purchase (NLA = no longer available). A few items are marked "Brief Impression", equipment which I used for a short time, but enough so that I could form a provisional opinion.
  • Meade Model #591 6" f/8 reflector
  • TeleVue Ranger
  • Celestron Cometron 90mm
  • Meade DS-10
  • Orion Short Tube 80 and Celestron F80 WA
  • Takahashi FS102
  • Astro-Physics Starfire 12 ED
  • Meade Starfinder 12" f/4.8 Dobsonian (Brief Impression)
  • Orion (U.K.) Europa 8" f/6 Newtonian
  • Meade 8" f/10 Schmidt-Cassegrain
    1) Meade Model #591 6" f/8 reflector (6" f/8 Equatorial Newtonian, clock drive, 25 mm, 9 mm MA eyepieces, $319, NLA)
    Meade #591
    Back in 1980, Meade sold this model as an economical alternative to their popular Model #628. The optics were the same, but the clock drive had nylon (instead of steel) bearings, and the tube was coated in a less expensive, less durable (as I was to find out) paint compound. Meade introduced this scope to compete with the popular Criterion Dynascope RV-6 ("Real Value") which sold for $299. This was the first telescope I bought. I waited 3 months to get it, which seemed like an eternity at the time. Every day I would get home from school and check to if it came. Keep in mind that Meade was not the dominant force they are today; at the time their products were just beginning to compete heavily with the more established Celestron equipment. Meade was bit of an unknown quantity. When it finally came, I remember being so impressed with the quality and sheer size of the telescope. It was much larger "live" than in its pictures. The parts were lovingly packed, padded, and in some cases re-packed. Looking back, it's easy to see why Meade has succeeded in the market- place. The Meade 591 was a real eye-opener, compared with my home made telescopes (I had built a few primitive refractors by this time). It was a quantum leap ahead of anything I'd seen up until then. If fact, when people ask me to recommend a good "first scope", I still point them to a good 4.5" - 8" reflector. The optics are decent. There's slight undercorrection, nothing serious. The figure seems very smooth. The clock drive is accurate enough for general observing. The verdict? I still have this scope, almost twenty years later. It sees a lot of "star party" duty. The paint on the tube has worn through and flaked off in many places. Hey, it's ugly, but it works! The new version of this scope is the Starfinder Equatorial 6 ($650). Update: 1/99 I donated this scope to my local club, and ordered a Meade 6" Starfinder Dobsonian to replace it. 2) TeleVue Ranger (70 mm f/6.8 air-spaced doublet refractor, ED glass, OTA only, 17 mm (old) or 20 mm Plossl (new) supplied, $850 list, $575-$650 street) (Note: See also related article)
    Ranger TeleVue's diminutive Ranger: A surprisingly versatile telescope.
    I need to disclose some personal bias here. I have a big warm spot in my heart for this telescope. It got me back into astronomy after many years due to its tiny size (16"-19", depending on how you store it), durable construction, and excellent optics. In fact, it's so small, you have no excuse NOT to go observing if it's clear out! As a result, the Ranger has shown me more than my other scopes combined. The heart of the Ranger system is a 70 mm ED objective with a 480 mm focal length. The focuser is helical, like a telephoto lens (the eyepiece does not rotate). You find rough focus with the draw tube, then you fine-focus with the focuser. Although it's well-made, I think I would still prefer a rack and pinion focuser. Switching between, say, a 40 mm and a 6 mm eyepiece results in some frustrating fumbling in the dark. The objective is not a true apochromat; the scope shows plenty of false color on bright objects. TeleVue classifies the Ranger as a "semi- apochromat". You can see a purple halo around the limb of Venus and the Moon, although the intensity is somewhat lower than on a traditional achromat. Otherwise, the Ranger performs like a champ. Stars snap into focus in a way that few reflector owners appreciate. Views of Saturn and Jupiter, and of deep-sky objects like the double cluster in Perseus, are quite stunning with the right eyepieces. You'd swear the aperture was a lot bigger than 2.7". With a 13 mm Nagler, the Ranger becomes a surprisingly good deep-sky instrument. It's actually easier for me to find M33 with the Ranger than with my 6" reflector. It's fun to see how "deep" this little scope will go. M81/M82 are no problem. M51 is no problem. M65/M66/NGC3628 are a little more difficult, but still relatively easy. M109 and M97/M108 are just about the scope's limit from suburban skies. With practice, however, I think I can go even deeper. You don't need a big scope to do deep sky! For planetary observing, however, it becomes difficult to acheive higher powers without resorting to tiny eyepieces and barlow-stacking. A 7 mm Nagler, for example, only yields 68X. You need to find a way to mount this scope. If you don't have TeleVue's excellent Gibraltar/Panoramic tripods, figure on getting at least a Bogen 3001, or equivalent. The scope attaches via a sliding dovetail bar using a 1/4" screw. You don't need a finder, but I did install a TeleVue Quick Point, and it helps. If you the idea of a Ranger, but want a rack and pinion focuser, consider getting a Pronto, which is the same scope except for the focuser and a 2" diagonal. It will run you about $850-$975 (street price, depending on options). 3) Celestron Cometron (90 mm Alt-Az Newtonian, 25 mm, 9 mm Kellners, $129, NLA) This little scope was released before Halley's Comet's arrival in 1986. It featured OK optics and a good table top tripod. Unfortunately, the eyepieces were .966", and the views were much dimmer than you'd expect for a 90 mm (a Questar or an ETX, for example, gives much better and brighter views.) Looking inside the focuser revealed why. To achieve a long focal ratio, the designers placed a small barlow lens inside the drawtube. I have nothing against barlows, but this one appeared to be uncoated and of poor quality. Also, removing it did not help. I experimented for a while by using 1.25" eyepieces and an adapter, but the results didn't get a whole lot better, so I sold it. 4) Meade DS-10 (10" f/4.5 Equatorial Newtonian, no drives, 9, 25 mm MA eyepieces, $499, NLA) Our club had one of these as our club scope back in the late 1980's. The optics were fair to good, but, as in any fast reflector, there was noticeable coma around the edges of the FOV -- forget about using any cheap 40 mm eyepieces! Also, you could not rotate the tube (it was bolted onto the mounting plate in the equatorial head), which got to be a pain after a while. The mount was a little wobbly, but its low height - the rear of the tube stood only about a foot or so off the ground - partially compensated for this. Despite the generally competent nature of this scope, it just didn't get used very often after the first year or so. 5) Orion Short Tube 80 and Celestron F80 WA (80 mm f/5 doublet achromatic refractors) (Orion ST: 25 mm, 10 mm Kellner eyepieces, OTA only, 45 degree diagonal, $249) (Celestron: 25 mm SMA eyepiece, equatorial mount, tripod, 90 degree diagonal, $349) (Note: See also related article)
    FS80WA
    These scopes share the same optics. I thought I saw a third version, a Vixen model, in a British astronomy magazine, but I can't be 100% certain. The Vixen sure looked similar, and it came with an interesting feature: it could turn itself into a microscope. You just point the objective lens down, slip on this corrector lens, and -voila!- microscope! Neat, huh? I've had the opportunity to look through 2 Orions and 1 Celestron. First, let me say that I like these scopes. They can't be beat for the price. If could somehow arrange to have these placed on department store shelves instead of "the usual" brand, there would be a lot more happy budding astronomers out there! Optically, these are rich-field scopes, sort of in the same class as the Edmund Astroscan. There is noticeable color around most bright objects (and usually a moderately bright purple halo as well). The Celestron I saw had pinched optics -- the diffraction rings were triangular. As long as you don't push the power too much, these are fine scopes for scanning the Milky Way, or for looking at brighter nebulae. Planets are a different story, though. With only 400 mm to work with, it's hard to get a sharp, steady image on Saturn, although the rings and Titan are well within reach. Jupiter was pretty (albeit tiny in the FOV!), too. However, as good as these scopes are, they do not deliver anywhere near the performance of, say, the Ranger/Pronto duo, which are in another class altogether. I am told the Brandons will also put these 80s to shame. Which one you buy depends on your needs. The Orion needs a tripod, comes with two eyepieces, and a 45 degree diagonal which should prove annoying in no time flat. The Celestron has only one eyepiece (but it's a better one than the Orion's), a 90 degree diagonal, and a decent equatorial mount with slow motion controls. For this, Celestron's asking price is $100 more. I think it's worth the extra, but if you already have the extra parts then you might do better to buy the Orion. 6) Takahashi FS102 (4" f/8 fluorite doublet apochromatic refractor, OTA only, $2625 list) (Note: See also related article)
    FS102
    The Takahashi FS102 is one of the "new" series in the Tak line and replaces the venerable FC100. In addition to the extra 2 mm of aperture, the most significant change is that the fluorite element is now in front; that is, ex- posed to the elements. According to Takahashi, the development of new "hard" multi-coatings (said to be even harder than the glass itself) allowed this change. Thus the FIRST thing the light hits is fluorite. I've been following the pro/con arguments regarding fluorite, (actually an artificially grown calcium fluorite crystal) and the prevailing "conventional wisdom" is that fluorite lenses are as durable as conventional glass elements. Still, I'd be interested in hearing from anyone who's had experience with this issue. The OTA arrived well-packed. I held my breath, opened the carton, and -whew- no damage to the optics. I had bought this used and had a few sleepless nights thinking about it -- visions of shattered glass danced in my head. What a beautifully made piece of equipment! If you've never seen one, the FS102 is LARGE for a 4"; the dew shield is 6" in diameter and almost 8" long. To give you an idea of the quality, the dust cap is made out of felt-lined cast iron, neatly sculpted, polished, and colored lime-green. It should last as long as your average man hole cover. Potential buyers should note that the price given above is for the OTA only. The finder ($130 for 6X30 mm, $275 for 7X50 mm) and mounting ring ($155) are sold separately. The reader will note that these items, like the scope itself, are NOT cheap. The OTA does come with a compression-ring style 1.25" diagonal. Like the rest of the scope, it's extremely well made, but if you want 2" capability it'll cost you another $100 or so for the visual back, and another $100-$300 for a 2" diagonal (you weren't really thinking about putting a $100 diagonal on this beauty, were you?) I eventually bought the 6X30 finder. It's extremely solid and delivers bright, pleasing images (it had better, for $130!). However, the "dew shield" is only about 1/4" long - the front lens is right out there, waiting to collect dew. The eyepiece is again held on with a compression ring, and has an incredibly smooth action to it. If you opt to go without the mounting ring, note that the Celestron/Vixen 102mm mounting rings, sold by Orion and others (about $72), fit the FS102 OTA perfectly. Once you have these rings, it's a simple matter to couple them to a Super Polaris or Great Polaris mount. OK, so it's not as good as Takahashi's EM2 ($1995), but it is about $1300 cheaper. I've gone observing quite a few times with the Tak now, in magnitude 5.0 New Hampshire skies, with a friend. Between us we have ten telescopes. It isn't hard to find dark skies in NH, but it gets cold quickly, and limits your ob- serving time to 2-2.5 hours in the winter, even with hot chocolate at your side! So we were able to compare the Takahashi with a number of different scopes. The closest competitor came in the form of an Astro-Physics Starfire 12 ED on a GM-8 mount. We ran some tests, but mostly we just went observing, looking at whatever struck our fancy. Both the A-P and Tak exhibited a tiny bit of undercorrection out of focus. In focus, the diffraction rings on both scopes looked as though they came right out of a textbook. Also, both scopes "snapped" cleanly into focus; there was no doubt as to where the focus point was. Using some crafty mixing of barlows, we managed to get both scopes at almost the same magnification on Saturn. I have to tell you, it was so close. Keep in mind that the Star 12 has something like a 39% advantage in light gathering ability; perhaps the extra-extra low dispersion of the fluorite element partially compensated for this. It was so hard to choose between them; we eventually gave up and just enjoyed the views. We briefly tried some high power viewing (200X +) but the skies weren't steady enough to support the magnification, and my Super Polaris is more wiggle-prone than my friend's GM-8. On another night, we caught a shadow transit on Jupiter (in daylight, no less!) Here, I did notice that the tiny black dot was more tightly resolved on the Takahashi. We trained both scopes side-by-side on Jupiter so we could quickly exchange views. I did notice that I was resorting to averted vision a little sooner on the Star 12. However, when the moon began to emerge from the limb of the giant planet, it was the Star 12 that found it first. On deep sky, the Star 12, with its larger aperture, slightly outperformed the Takahashi. M33 and M42 were a little brighter, for example. But the differences, like those described above, were small. They both looked so good. M42, with a 25 mm TeleVue Plossl and a UHC filter, just about filled the view with a swirling mass of green in both scopes. Our 6" and 8" Newtonians are brighter, but the refractors seem to show more detail, and are much sharper. Replacing one of the elements in a conventional achromat with a fluorite element (FPL53) should result in about a 45%-50% reduction in chromatic aberration ("false color") compared with "ED" (FK01) glasses. "ED" in turn, exhibits about 70% less chromatic aberration compared with conventional crown-and-flint achromats. In theory, fluorite should reduce false color to below the level of detectability. I did train the Takahashi on Venus briefly. While it was "whiter" than any other refractor I've looked through, I thought I could see some red on the limb of the planet. Note that Venus was low in the sky, and I was using a "complicated" eyepiece (a 9 mm Nagler) which has shown some color on its own. So the jury's still out on this one. Both instruments are beautifully finished. It's obvious both companies care about their products. I'm biased, but I admit to being attracted to the somewhat understated (pale lime green) finish of the FS102. And Takahashi's much-vaunted focuser is simply incredible; if you haven't used one, you should someday (and the Star 12's focuser is no slouch, either!) I did think that the visual back and extension tube assembly were a bit better executed on the Star 12, however. In short, I'm extremely pleased with my new Takahashi. I expect it will give me much pleasure in the years to come. 7) Astro-Physics Starfire 12 ED (120 mm f/8.5 doublet ED refractor, OTA only, $1999, NLA) It is hard to believe you could once get these scopes for $1999. The current waiting list for A-P refractors stretches out to over a year. People sign up for a waiting list just to place an order. Then, after plunking 50% down, you wait another 9-12 months before you get your scope. Clearly, some- thing is going on here. What is going on is that Astro-Physics produces some of the finest telescopes in the world today. In the rarified air of high quality refractors, only Takahashi and perhaps the Vixen fluorites are their equal. The version I used was outfitted with a Meade 2" diagonal and a Meade 8X50 finder on a GM-8 with dual-axis correctors. My friend bought it from someone at the Suffern show who was moving up to a larger A-P. What can I say about the views, they were exceptional. I thought I could see some false color (very slight) on bright objects, and perhaps the color was a little more pronounced than on my Takahashi, but it was minor. The Star 12 is no longer made. Roland Christen replaced by either the A-P 105 Traveler, or the A-P 130 EDFS, depending on how you look at it. The new A-P units are all oil-spaced triplets; the Star 12 is an ED doublet (presumably air-spaced). I have not looked through any of the new Christen triplets yet, but they are said to have no false color whatsoever. For further comments, see above under Takahashi. 8) Meade Starfinder 12.5" Dobsonian (Brief Impression) (12" f/4.8 Dobsonian, 6X30 finder, 9 mm, 12 mm, 25 mm MA eyepieces, $895) During First Night (New Year's Eve, 1997) our club sponsered a Sky Watch for the public at the planetarium in Concord, NH. The owner of this scope wound up inside the planetarium for most of the night, so I got to play with his Star- finder (showing it to the public, etc) for about 1.5 hours. Thus this is a brief impression. These has been much debate on the 'net as to the quality of the optics and mount on this scope. Reports have it that the mirror won't cool down and that the mount is flimsy. I found neither to be true on this particular sample. The scope did exactly what it was meant to do -- gather lots of light, cheaply. I have to wonder about those who compare large dobs like this one with expensive APOs; there really isn't any comparison, since the two designs have complimentary strengths and weaknesses. I like going observing with large dob owners. I bring my 4" refractor and we can compare views. The optics were quite sharp, more so than I expected. In addition, there is surprisingly little coma around the edges (but if coma bothers you, it IS there). These scopes were built to look at objects like M42, and there was no disappointment in this area. The nebula looked splendid! With a focal length about midway between a 6" f/8 reflector and your typical Schmidt- Cassegrain, the Starfinder was actually pretty good on Saturn. At least 3 moons were visible, with a fourth "blinking in" every now and then. I ran a quick star test. In the center of the FOV, the first diffraction ring was quite prominent, with a small airy disc in the center. As you move out towards the edges, though, the diffraction pattern becomes "V" like, not very pleasing. Hey, what do you want for only $895? Update, 4/00: Meade recently reduced the price of this telescope to $795, + $79 shipping. 9) Orion (U.K.) 8" f/6 Newtonian (8" f/6 Newtonian, 6X30 finder, no drives, eyepieces, $1250, mount only, $549)
    Europa 8 The Europa aboard a GM-8
    A good set of optics on a too-light mount. This is the British "Orion," not the Orion in CA, USA. They offer 4.5", 6", 8", 10", and 12" re- flectors mated to a Taiwanese German equatorial mount. Unfortunately, the mount is asked to bear the weight of the 6", 8", and 10". In reality, it is more suited to the 4.5", or something even lighter. The owner of this scope figured out how to mount the 8" OTA to his GM-8 and reports good results. In my time with the scope the images looked promising, and seemed a cut above the Meade/Celestron units. I'm told the OTAs are available separately. Update, 7/98 Having used this scope a number of times, I've been increasingly impressed with its optics. It's better than your run-of-the-mill Newtonians, giving very sharp images. Worth seeking out, if Newtonians are your thing. Just have a good solid mount handy. Update, 12/99 According to Barry at Orion (UK) Optics, these reflectors will be shipping with a heavier mount starting January, 2000. This is certainly welcome news, and will make these telescopes even more appealing. 10) Meade 8" f/10 Schmidt-Cassegrain (8" f/10 fork-mounted S-C, drives, finder, 25 mm MA or 26 mm Super Plossl) (LX-10 version: $995 + $195 for tripod) (LX-50 version: $1395 + $295 for tripod) (LX-200 version: $2295 complete) Every time I see one of these things, I'm amazed at how compact the are. Looking somewhat like overgrown coffee pots, they're easily transportable out into the field. The tripod is relatively light, too. Yet, in spite of their portability, you still get a generous 8" of aperture. No wonder they're so popular. Once set up, these Schmidt-Cassegrains deliver good, and sometimes very good, performance, although rather consistently below the performance of good apochromatic refractors. I do notice some variation in quality, mostly due to miscollimated optics. This is easy to spot. Rack the focuser out a bit and look at the image. If the alignment is off, it's immediately obvious. These make good planetary scopes, though I feel kind of "boxed in" with their relatively narrow fields of view (forget about looking at the Pleiades). Also, these scopes can take somewhat longer to cool down than small refractors or equivalent-sized Newtonians. The corrector plate is subject to dew; a dew shield of some sort is a necessity. Also, image-shift while focusing takes some getting used to, especially for non S-C owners like myself. What's more, the amount of image-shift varies from scope to scope. Finally, using cheap eyepieces can result in some annoying ghost images in the FOV (ironically, the supplied MA25 eye- piece in the LX10 and LX50 units is a particularly bad offender). These are good scopes to use if it's windy out -- there's less surface area for the wind to grab. Also, when it comes time to break down at the end of a cold observing session, Schmidt-Cassegrain owners are usually the first ones back inside their warm cars. I won't go into the differences between the LX10, LX50 and LX200 versions; to do so would require another separate article in itself. Suffice it to say that the optics remain the same, but the mechanical and electronic sophistication in- creases as the model number increases. The LX50 and LX200 are a little more stable than my Super Polaris, the LX10 perhaps a bit less so. End Reviews, Page 1
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