Telescope Reviews
Page 12
By Ed Ting
Updated 11/6/02
Click on a Telescope Below:
1) Stellarvue 80 mm f/6
2) TeleVue 102
1) Stellarvue 80 mm f/6 6/23/00, 7/21/01, 5/21/02, 11/6/03
(80 mm f/6 cement-spaced achromat, diagonal, 25 mm, 9 mm, 6X30 finder,
rings was $279, with equatorial mount, $479, no longer available)
(Note: Scope has been replaced with AT1010 model)
They say first impressions count for a lot.
In this case, my first impression of Stellarvue came at this year's (Y2K) NEAF
trade show. They had a booth, which is nothing unusual. What was a bit
unusual was its arrangement. Apparently Stellarvue head honcho Vic Maris
couldn't make the trip, so one of his customers, who believed very strongly
in the product, volunteered to set up and man the booth for the entire day in
his place. Most manufacturers would kill for loyalty like this.
Maris says on his web site that his motivation for producing these telescopes
isn't money; rather, it's a labor of love. It's nice to hear these sentiments
expressed, but he needn't have said it. Stellarvue's devotion is obvious, from
the high quality of the product, the attention to detail, the outstanding customer
service, and the low price.
This little telescope generated more advance e-mail on this web site than any
other piece of equipment, ever. Every morning in May and early June of 2000,
I would get up and write "I haven't seen it yet" to (now) countless online
amateur astronomers. Reports from owners had been trickling in (almost
all reporting good news) but I wanted to see one for myself to see how well
it did.
What's all the fuss about? This is a new twist on these inexpensive achromats.
Vic Maris uses lenses of Stellarvue's own proprietary design, and assembles an
OTA with special attention to collimation, baffling, etc. The result is like
having only the best samples of these achromats available from one source,
mounted in a heavier-duty tube assembly.
Recommended...But there is a catch
The scope is extremely well-built, and much heavier than the run of the mill
achromats you are used to seeing in this price range. The tube is very short
-- at first glance, you might guess the scope is an f/4, not an f/6. There's
a long focuser drawtube inside. We used Stellarvue's 1X finder, which looks
like a TeleVue Quik Point with a giant window up front. A version with a 2"
focuser is said to be in the works.
The rings are threaded for 6 mm, not 1/4" X 20, so watch out. Also, while the
rings are spaced for use atop an Orion Sky View Deluxe -type mount, they cannot
be spread far enough apart for use on an SP/GP without the use of a makeshift
adapter -- yes, the tube is that short. (Maris says he is developing an SP/GP
plate.)
We set up the Stellarvue 80 on a Super Polaris. For comparison, we had a TeleVue
Pronto, a C102HD, and a 4" f/5 Skywatcher. As a reference standard, there was a
Takahashi FC76 nearby. The Tak quickly established itself as the best telescope
in the field and was never even remotely challenged throughout the evening. Three
observers were present, all of whom participated in the Three Way Super Comparo,
which you may have already read.
The star test on the Stellarvue was superb - almost no color on Arcturus at 68X
and excellent spherical correction. The star test was second only to the FC76
and was actually better than my $1100 Pronto. In addition, contrast was very
good. At high power, stars were round little balls with no sprays of light
anywhere, which is very unusual for an achromat in this price range. Epsilon
Bootes was cleanly split, as was Epsilon Lyrae. If you are thinking of buying
a telescope in this size and aperture range, look no further, the Stallarvue
is the one you want. But...there is a catch.
The Stallarvue walked all over the 4" f/5 Skywatcher, and it was retired for
the evening in favor of the C102HD. Still, while many of us like C102HDs,
it isn't really in the same class as this short tube achromat, and it didn't
get used much through the rest of the evening.
So this test quickly settled down to a battle between the Stellarvue and the
Pronto. Based on the star test and the splitting of some doubles, two out
of three of us seemed to be leaning towards the Stellarvue, which at first
seemed to be performing miracles at every turn. There was less false color,
and the sky background was blacker. The images were universally dimmer,
however. If you want one of these scopes, go ahead and buy one now before
the waiting list gets to be too long. I'm telling you, it's OK with me. But...
there is a catch.
On deep sky, the Stellarvue was dimmer than its 70 mm competition - I could
consistently see deeper in the Pronto despite it having less aperture. This
was most apparant while viewing the Ring and M13. There were stars I could
see in the Pronto that were invisible in the Stellarvue. Still, the Stellarvue
held up well, and all of us were impressed by its ability to take high power.
So...you should get one. Really. I'm not kidding. This is not a joke.
But, HEY, DIN'CHA HEAR?! THERE'S A CATCH!!!
All right, all right. Here's the catch. Something was bothering me all
night long. I couldn't put my finger on it, but something just felt wrong
in Mudville tonight.
Compared to the Pronto, the Stellarvue has more aperture, a shorter f/ ratio,
and no special dispersion glasses in its optics. Any one of these factors
should make the scope throw up MORE chromatic aberration. Yet, it has
LESS false color. Something wasn't right. Between the apparent lack of
false color, the near perfect star test, the large airy discs, and the dim
images, I began to suspect the scope had been intentionally stopped down.
This isn't exactly the case, but my guess was close.
We took off the dew shield and measured the objective lens -- 80 mm.
But, looking down the tube, I saw the solution to what had been bothering
me. The focuser drawtube, as indicated before, is really long. Even with
TeleVue eyepieces (which take a lot of out-focus travel) the drawtube
protrudes almost halfway up into the OTA and cuts off a chunk of the
incoming light.
People have been using aperture masks to "improve" their optics for hundreds
of years, so this is nothing new. Measuring the exit pupils with eyepieces
of known focal length yields an approximate equivalent clear aperture of
around 67 mm for this sample.
So the Stellarvue is really something like a 67 mm f/7.16 telescope, not an
80 mm f/6. You're losing 31% of the light grasp and trading it off for image
sharpness. And that's the catch. How much of an issue this will be, however,
depends on the individual. Each potential customer will have to form their own
opinion on this design strategy.
(Note, 6/23/00: According to Vic Maris, the effective aperture should be
closer to 70 mm with a diagonal in place. It will be higher without a
diagonal. Also, Maris states the 2" version will have less light cutoff
than the 1.25" version, at a modestly higher price.)
As stated before, this is a really nice telescope. Even if it's only 67 mm,
I'd rather have a smaller scope that's sharp, rather than a bigger one that
throws up mushy images. I should also state that I do not believe that an
average 80 mm achromat, purchased randomly off the shelf and manually
stopped down to 67 mm, will achieve the same level of performance as this
Stellarvue. The careful selection and collimation of the optics by Stellarvue
does account for much of the little scope's impressive performance.
I'll take sharp telescopes any way I can get them, and $279 for a nice,
hand-assembled, hand-tweaked refractor is still a major bargain. Another
way to look at this is, you are getting something very close to TeleVue
Ranger performance, at 1/2 to 1/3 the price. And that's nothing to scoff
at.
Recommended.
Update, 7/01: Vic Maris has been busy making changes to these Stellarvues
in the year since this review appeared. Newer versions have shortened tubes,
which is said to result in an effective clear aperture in the 70mm-75 mm range.
Also, Stellarvue now designs its own lenses, which are sourced from many
suppliers. There's also a new "deluxe" version which features a Vixen 2"
focuser. A version with a Crayford focsuer may also appear in the future.
I have not seen any of these new units.
Update, 11/03: After reading this review, check out the AT1010 which replaced this
model. The AT1010 units feature a number of improvements, including a full 80 mm
aperture.
2) TeleVue 102 7/1/00
(102 mm f/8.6 doublet apochromatic refractor, OTA and case only, $2050)
(Note: see also the Todd Gross review of the same telescope)
(This sample was provided by Anacortes Telescope and Wild Bird.)
This is TeleVue's newest refractor, and one of its best designs ever. I
was immediately won over by its sharp images, the simplicity of its
design, its well-constructed mechanics, and the attractive price.
The Zen of Al Nagler?
The TeleVue 102 on a Gibraltar
The scope is a bit of a departure for TeleVue. Instead of coming out with
yet another complex optical design, the TV102 uses a simple, well-corrected
doublet. I've often wondered in the past if there was an informal competition
among TeleVue designers to see who could cram the most lenses into their
products (JUST kidding, Al...) Open case and you'll be surprised as well.
Where's all the...all the...STUFF that usually comes with a TeleVue scope?
There's no diagonal, no eyepiece, no finder, no tube ring even. Call it the
Zen of Al Nagler.
I'll risk World War III by saying this, but I think the simpler doublets in the
TeleVue 85 and this TV102 are consistently sharper, clearer, and more
contrasty than the more complex four-element-in-two-groups systems in
the TV101/Renaissance duo (and the old Genesis sdf.)
At 10 lbs, the tube is very light - lighter than the TV101, which has the
extra elements. Also, the tube on the TV102 seems to be made of a slightly
lighter weight material as well. As a result, the OTA can easily be handled
by a GP/CG5 type mount. The focuser is the same super-smooth unit found
on all TeleVue scopes. The foam-lined case is almost a work of art.
Screwing off the metal dustcap allows you to extend the dew shield and
see the dark coatings on the lens. And what a fine lens it is! We set
up the TV102 next to a Celestron 102 f/9 ED, and my new Astro-Physics
Traveler, on three successive nights. You're expecting me to tell you
that the Traveler wiped the field with the other two, but it wasn't that simple.
All the scopes performed superbly, and any differences were slight at best.
All three scopes threw up an impressive star test; I'd estimate a stingy 1/8
wave on the TeleVue, with a smooth figure, no astigmatism, and only very
slight false color.
In fact, it wasn't until late in the second evening that we began to express
some preferences; namely, the TeleVue and the AP seemed to be doing
slightly better than the Vixen-based Celestron 102ED. The airy discs were
sharper, and there seemed to be slightly less false color in the TV and AP
scopes.
It's interesting to note the different philosophies regarding baffling on
these telescopes. The Traveler uses AP's standard-issue "ridges", which
look a bit like jagged acoustic foam lining the tube. The TV102, like all
TeleVue scopes, uses no baffling at all - the interior of the tube is lined
with black flocking paper (any remaining stray light is said to be handled
by the cut ridges on the TeleVue diagonal.) Finally, the Celestron uses
conventional knife-edge baffles. The result of this is that the Celestron
winds up having the biggest, thickest, heaviest tube, while the TeleVue
is the narrowest and lightest.
You might expect the AP and Celestron baffling systems to work better
than the TeleVue's, but again this wasn't the case. Contrast, sky blackness,
and glare were well-controlled in all three scopes. I couldn't tell any diff-
erence between them. Maybe there's something to be said for simplicity.
As noted before on this site, one hallmark of a good telescope is its ability
to get me out of "reviewer mode." By this measure, the TeleVue 102 is a
very good telescope indeed. I couldn't wait to get the boring test-stuff out
of the way so I could start using it.
In keeping with the scope's "simplicity" theme, it was used without a finder.
TeleVue sent a tube ring and Starbeam, but they arrived too late for the
photo shoot. The hinged rings supplied with inexpensive achromats like the
C102HD and its offshoots do fit around the narrow tube of the TV102.
We spent time looking all the common summer objects. Izar was split wide
open, as was Epsilon Lyrae. The 13.1 magnitude star next to the Ring Nebula
was seen in direct vision in all three scopes. All four members of Nu Scorpii
were glimpsed at 350X in patches of good seeing, even the .9 arc-second pair.
Delta Cygnus was split as well; as with Izar, the glare of the bright primary
stayed put so that the tiny secondary component could be viewed.
It's my curse to have been involved with some really nice refractors lately
(the 4" Carton, the Stellarvue, and this TV102) with no planets to look at,
but I hope to remedy this in the near future. The TeleVue is due back to the
dealer soon, though - pity. On deep sky, M27, M13, M3, M8, M20, M22,
M81/M82, and many other objects were viewed.
Like all great telescopes, the TV102 soaks up high power with poise and
composure. The slight chromatic aberration came into view only at stupid-
high powers, and only when viewed immediately after the same stupid-high
view on Vega through the Traveler. In fact, this high power false color test
was the only measure in which the expensive AP could be said to have
readily beaten the TV102. In virtually all other side by side tests, I could
not tell the difference.
The TV102 rewards any upgrades you care to throw at it. Substituting an
AP MaxBright diagonal ($300) for the standard-issue TeleVue unit tightened
things up even further. This was most evident on M17; even novice observers
present could tell the difference. TeleVue's EverBright ($260) would likely
have the same effect. Using Panoptics and Naglers also made the images
more pleasing and gave more of that TeleVue "spacewalk" effect. The point
is, the TV102 is good enough that the scope is not the limiting factor in per-
formance. You could build a whole observing system around one.
Two fine tubes: the TeleVue 102 (top) and
the Astro-Physics Traveler (bottom)
As stated before, the scope is sold as an optical tube assembly and case only,
so if you are just starting out, you need to place the following on your shopping
list: the TeleVue tube ring ($120, mandatory) a good 2" diagonal with 1.25"
adapter, a Quik Point or Starbeam, and a mount like the Gibraltar (above) or
something in the Super Polaris/Great Polaris/CG5 class. Add some good
eyepieces and you'll be all set.
On the other hand, experienced observers who already own a refractor or
two will be pleased that they aren't forced to buy yet another 2" TeleVue
diagonal and 20 mm Plossl. Piecing out the parts of the scope like this
is a good idea.
$2000+ for an optical tube is a lot of money for a telescope, but in the
premium refractor world, it's a bargain. In fact, I think the TV102 is
so attractively priced, it may start stealing sales from the TeleVue 85
(around $1900 with the diagonal, case, and eyepiece.)
The new TeleVue 102 combines great optics and solid mechanical con-
struction in an attractive package. It takes its place, along with the AP
Traveler, the Takahashi FS102, the TMB Fluorostar, and the Vixen/Orion
fluorite as one of the great 4" refractors available today. It's a solid value
as well. If you're in the market for a premium apochromat in this size,
the TV102 is enthusiastically recommended.
End Telescope Reviews, Page 12
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