Telescope Reviews

Page 20 By Ed Ting Updated 1/28/04

Click on a Telescope Below: 1) Astro-Physics AP130 f/6 refractor 2) Orion Skyquest XT10 Dobsonian 3) Orion Skyquest XT4.5 Dobsonian 4) Stellarvue AT1010
1) Astro-Physics AP130 f/6 2/1/02 (130 mm f/6 oil-spaced apochromatic refractor, rings, case, OTA, $3950) Apochromatic refractor users are a breed apart. In some ways, they remind me of audiophiles who will only listen to single-ended triode amplifiers. In both cases, users will shell out enormous sums of money for a device that, at first glance, seems to lack any kind of power. SETs and APOs do have their limitations, of course, but used intelligently within certain bounds, they can be astonishingly accurate. Just as many budding audio- philes have had their ears opened by listening to a $4000 vacuum tube amp pushing out a measly 3 watts, I've seen new observers practically fall to their knees at their first view of Saturn through a good APO. Astro-Physics introduced the f/6 version of the venerable AP130 a few years ago. The f/8 version drifts in and out of the lineup, but it looks like this f/6 version has taken its place as the "standard" 5" AP refractor. If you're familiar with the f/8 version, the f/6 is going to look really tiny to you. The case has no side handles, two buckles instead of four, and looks way too small to hold a 5" refractor. Everyone who saw it remarked on its small size. It is sooooo cute.
Another beauty from AP: the 130 mm f/6
These AP reviews are getting hard to write. Each one is as perfect as the next one. This one has no aberrations that I can find, even at very high power. We put this scope up against the f/8 version one evening. Despite the longer scope's technical advantage, I could see no difference between the f/8 and f/6 scopes even at low power. I even tried to induce coma at the edges by putting in cheap low power eyepieces, but the 130s (both of them) refused to budge. Impressive.
It's smaller than you might think
This sample gave razor sharp, so-good-it-doesn't-look-real images of Saturn, and we caught a shadow transit on Jupiter later on. As the moon exited the limb of the planet, it gave the appearance of being a tiny, round wart growing off the surface. When the air settles down, the sky's the limit as far as magnification goes. 400X, 500X, no problem. Around here, with the rig we had set up, the atmosphere and/or the mount gave out before the scope did. The Orion Nebula is beautifully framed with a 17 mm Nagler and an OIII filter. As for the mount, we used an AP400, but the scope is so small and short that a GM8 would do nearly as well up to 300X or so (the GM8 is marginal on the larger f/8 version.)
You'll be the center of attention with one of these
As with any AP product, there is a substantial wait to get one. I don't know the current status of the waiting list for this model, but you should expect a wait of at least two years if you notify AP today of your interest in obtaining one. Again, my advice is to get on the list if you think you want one, then forget about it. Go buy a telescope, go observing, then hopefully you'll get a phone call from AP sometime down the road. Also, if you do not have a mount, finder, diagonal, etc, you need to budget your needs accordingly. Assembling a first-rate rig around this optical tube can easily run you another $2000-$5000. I hate to use the "P" word in a review, but there it is, again and again, in my observing notes: "Perfect resolution", "perfect pinpoint images", "remarkable color shading on Saturn", "beautiful split on a tight double, no light scatter", "perfect star test." On a recent evening in Concord, NH, our observing group was putting on a skywatch in conjunction with the local planetarium. This AP130 was present. A woman walked up to the scope and looked at Saturn. In the dark, nothing seemed out of the ordinary. She looked for a few moments, then went back inside. I found her inside a few minutes later. She was crying. "It's so beautiful," she said. I mean, can there be any higher recommendation than that? 2) Orion Skyquest XT10 Dobsonian 2/1/02, 3/2/03 (10" f/5 Dobsonian, 25mm, 9mm Plossls, 8X50 finder, moon filter, $649 + shipping) Here's another impressive entry in Orion's budget XT Dobsonian line. All of the attributes of the XT6 and XT8 (both recommended) are here, in a larger and heavier package. The optics are decent, the motions are reasonably smooth, and (perhaps most importantly) it's not a work-in-progress like some of the other entry level Dobs out there. Once it's assembled, it's quite usable right out of the box.
A good scope for ambitious beginners - Orion's Skyquest XT10
There are some nice touches. The focuser is a 2" metal rack and pinion unit, and you get an 8X50 finder. I've seen lots of these at star parties and the scopes seem consistent enough for me to recommend them. I was finally able to get the use of one in my driveway for a thorough test. Unfortunately, this sample had the least impressive optics of all the ones I've seen. The star test revealed close to 1/2 wave of overcorrection, and the primary appears to be astigmatic as well. While this is of some mild concern, I'll chalk it up as a stray data point since all of the other XT telescopes I've seen have had good optics. I spent an enjoyable night looking through the scope at an impromptu star party. Also present were the TeleVue 102, AP130 f/6, AP130 f/8, 11" Starmaster EL, and the big 16" Meade Dobsonian. Despite being the least expensive telescope present, it never lacked for people wanting to look through it. We toured the early winter Messier objects and looked at Saturn and Jupiter. While it didn't pose a serious threat to the premium scopes present, the XT10 performs competently on all types of objects. It gathers enough light to use an OIII filter, and better eyepieces helped things considerably. Those good eyepieces should probably be your first upgrade. The scope handles the 27 mm and 35 mm Panoptics, and even the huge 31 mm Nagler quite well. The latter showed some coma at the edges, so I tried inserting one of TeleVue's new Paracorr units. Even with 4 lbs of overhanging weight (not to mention $1000 worth of glass) hanging off the front of the scope, the spring tension system held the optical tube in place. Not that many of you are going to do this, but it's nice to know you could. You should be aware though, that 2" TeleVue eyepieces barely come to focus on the focuser's outer travel limit. I had to clamp the Naglers and Panoptics off the focuser tube with the set screw to find focus. I didn't experiment with moving the mirror up in the cell, but presumably this would help things. I've noticed this on several XT10s I've seen; perhaps that's just the way the mirrors are set from the factory. Beginners should note that this telescope is much larger than it appears in the photo above, and in Orion's catalog. The 58 lb weight (35 lbs in the tube alone) may make it uncomfortable for transport by one person. Consider building a rolling dolly or platform for it. Also, the eyepiece rack is largely cosmetic; once you experience the thrill of having all your eyepieces dew up at once in it, you'll go back to using a conventional eyepiece case. These Orion XT Dobs are all successful. Their success comes from not doing anything glaringly wrong. The mechanics are good, the optics are good, the accessories are decent, and the price is reasonable (but not so low that the quality suffers.) In a way they remind me of the 2001 New England Patriots. There was no one outstanding aspect of the team. But they minimized mistakes, and played just well enough on offense, defense, and special teams to win games, and quietly rose to the top. Orion seems to have found a similar sweet-spot with these Skyquest Dobs, and the amateur community is indebted to them for their efforts. It's a solid package at a reasonable price. Recommended for observers moving up from a 6", or for ambitious beginners. Update, 2/4/02: A few of you have written in to tell me that your XT10s also have modest spherical aberration. So it does appear that there is some optical variation between units. Update, 3/2/03: I've seen two more of these XT10s in recent months. Both have had really nice optics. One retained a sharp image on Saturn at 400X+, something I would not have believed had I not seen it myself. Also, the XT user's group on Yahoo describes a nice mod for the azimuth bearing using ebony star and magic sliders that frees up the motions. Check it out. 3) Orion Skyquest XT4.5 Dobsonian 2/1/02 (4.5" f/8 Dobsonian, 6X26 correct image finder, 25 mm, 10 mm Plossls, $199+) The room went quiet as the the people in the room settled down in their seats. "This meeting of Scopeaholics Anonymous will now commence." A little woman got up to the podium and introduced herself. "Hi, my name is Peggy, and I'm a Scopeaholic." Murmurs greeted her. "My problem is...well.. I don't know if I can tell the difference between all those TeleVue eyepieces. I mean, the Radians, the Panoptics, the Naglers - they all look pretty much the same to me." She sobbed, then stepped down. Several men got up to console her. "That's all right," I heard one man say. "You're among friends. This is a place to admit these things. The healing can start now." A young man got up. "Hi, my name's Greg, and..." he hung his head in shame. "I...I've never understood how to properly read a star test! I defocus stars in my scope, but I'll be darned if I can tell what those little patterns mean!" He collapsed in a heap in his chair. "There, there," said a man, gently nodding. "That's what we're here for. To help astronomers confess their insecurities and lead more normal lives. Now, there's a young man in the back of the room who's here for the first time. Yes, you...the geeky pale-faced guy in the Carl Sagan T-shirt." I stood up amidst the crowd. "My name's Ed, and I'm a Scopeaholic." "Hi Ed," greeted ther crowd. "Well, I...uh..." The crowd leaned forward in their seats. "Uh...well...the 4.5 inch is now my favorite model within the XT line." "What??" said a man in crowd. "The smallest model? That kid's scope?!" "Yeah, I mean...well...I like the other XTs, but the little 4.5 is so well-made, hardly costs anything, no one has an excuse for not having a telescope any- more with this thing on the market, it's such an overachiever-" I didn't get to finish; the room had erupted in laughter. Men were slapping their knees; women were laughing so hard they began wiping the corners of their eyes with tissues. "That little thing? You mean, you mean..." I lost the rest as the man doubled over with laughter. A red-faced, barrel-chested man wearing overalls stood up: "Son, even EYE gots me an XT6 back at the trailer!" I sat up on the couch in a cold sweat. I'd fallen asleep with an Orion catalog in my lap and my cat was eyeing me curiously. (Yes, I've already used this cheesy it-was-all-a-dream plot device on this web site, but do me a favor and suspend your disbelief for a few moments, OK?) Introduced last year, this super-cute Chinese-made 4.5" f/8 Dob from Orion turns heads everywhere it goes. The photo below does not begin to show how small the scope really is. The eyepiece only sits about 3 feet off the ground, making it the perfect height for kids. Unlike previous 4.5" Dobs from Orion and Celestron, which featured a shaky single-sided swingarm design, this one has a real three-sided rocker box and Orion's spring tension system. Couple this with the remarkably small size of the unit, and you have one unusually rigid little scope.
A good scope for beginners and Scopeaholics alike: Orion's tiny Skyquest XT 4.5
The base is an oversized triangle with sturdy feet attached, which prevents scope tipovers in the middle of the night. There's a convenient carrying handle on top, which allows you to pick up and move the scope with one hand (it only weighs 17 lbs so even your kid will likely be able to move it.) Ambitious kids could probably even handle the assembly too (figure about 20 minutes for an adult.) This sample has slightly undercorrected optics. The primary may, in fact, be spherical (Orion's catalog won't say either way.) If the scope ever goes out of collimation, the unit is fitted with a bona fide four-vane secondary spider to help you with alignment (previous inexpensive Dobs in this series used a maddening single-vane secondary.) The primary cell has generously sized push pull adjustments too. The finder is of decent quality, although experienced observers might have trouble with the correct-image optics. I liked the two-screw "sprung" finder bracket. About the only thing I didn't care for was the plastic (1.25" only) focuser. Although it's much sturdier than the plastic focusers from Meade, I have some concerns about its longevity. It's mean for me to complain about this one component on a $200 telescope -you can spend almost this much upgrading the focuser itself!- but it's worth mentioning. Also, I found the "navigation knob" to be of limited usefulness. Just grab the scope and move it. Also, the scope seems to top out around 125X or so, and the eyepieces are modest in quality. But hey - you're getting an entire telescope for the price of one nice planetary eyepiece (like a TeleVue Radian.) The telescope gives remarkable views for the money. I spent some time at a skywatch, kneeling down in the grass, picking out object after object on a dark night. I caught about twenty Messier objects and could have done much more, except my legs were cramping up. This was a public star party night, and members of the general public, sobered by the costs of the AP refractors and Zambuto-equipped Starmasters in the field, were pleasantly surprised to hear how little the XT4.5 cost. The views of Saturn and Jupiter were crisp, clean, and detailed (not to mention solid, given the scope's beefy construction and low center of gravity) and it gathers just enough light to pull in the show- piece deep sky objects. I usually recommend against buying a telescope under about $350. But this cute little XT won my heart and my enthusiastic recommendation. It would be a bargain at $300. The fact that it costs $199 can only be considered a happy bonus. It doesn't matter if you're an old hand, or a newcomer to the hobby, you should seriously consider getting one before Orion stops selling them, or raises the price. And yes, this 4.5" really is my favorite in the XT line. That's all for now - time to get ready for the next Scopeaholics Anonymous meeting. 4) Stellarvue AT1010 4/1/02, 5/21/02, 1/27/04 (80 mm f/6 achromatic refractor, OTA, 1X red dot finder, rings, $399) (Note: Price was reduced from $449 to $399 in Jan '04) (With equatorial mount, $699) The AT1010 is the newest (and best, so far) version of Stellarvue's popular 80 mm f/6 achromat. It adds a 2" focuser, large rubberized knobs, and a redesigned lens cell. For those of you who are new to this, Vic at Stellarvue uses lenses of his own design. These proprietary lenses are matched by hand, and each scope is individually star tested before shipment. The personal attention to detail means that a Stellarvue will almost always outperform cheaper, generic units. For this, you pay a little extra. This one is $399.
The AT1010 on a Gibraltar
I used this sample (supplied by Stellarvue) over several nights. Vic assured me it was a random sample, but he didn't have to. You've shown me many of your Stellarvues at star parties, and they do seem very consistent. The scope was mounted on a Super Polaris, a TeleVue Gibraltar, and the Unistar mount from Universal Astronomics. If you have one of those generic Chinese Sky View Deluxe-type mounts, it will hold the tube just fine. The star test was impressive, with virtually no spherical aberration seen. False color is about what you'd expect from an 80 mm f/6 achromat - hard to see on deep sky, but getting stronger as you look at brighter objects like Sirius, Saturn, the moon, and Jupiter. Cassini's division is easy, as are shadow transits on Jupiter. Izar was split at only 80X - not bad for an 80 mm achromat. The new 2" focuser is fun to play with - I inserted a 27 mm Panoptic and caught M81 and M82, and saw M31, M32, and M110 in the same field. The Double Cluster is a nice sight, too. The larger focus knobs helped in cold weather. Unlike some scopes, I didn't have to remove my gloves to focus. The red dot finder has a larger window than the Rigel Quik Finder, which makes it slightly easier to use. Like other Stellarvues, the AT1010 is a safe, reliable, if somewhat boring, recommendation (that's supposed to be a compliment; their consistency is so good they're boring.) Vic is an inveterate tinkerer, and is working hard to relieve the boredom with new 102D, 102EDT, and 102APO refractors that are designed to compete with the big boys. Also on the docket are 85 mm apochromats in two different focal lengths. Based on the quality of the technical emails I get from him he appears to be very serious about entering the high end. An early production sample of the 102EDT, a triplet near-apo with a 2-speed rotating Crayford focuser, looked very promising. Stay tuned, we'll be hearing more from Stellarvue in the near future. Recommended. End Telescope Reviews, Page 20
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