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By Ed Ting
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.
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
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.
End Telescope Reviews, Page 20