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By Ed Ting
Click on a Telescope Below:
1) (Orion) Skywatcher 120 mm refractor
2) Celestron C9.25
3) Pentax 75 SDHF refractor
4) Takahashi FS152
5) AP180 EDT
6) Orion Executive Brass Mini Telescope
1) (Orion) Skywatcher 120 8/7/00
(120 mm f/8.3 air-spaced achromat, 6X30 finder, rings, about $425 street)
(Orion version: with equatorial mount, 2 eyepieces, 1.25" diagonal, $599)
The Skywatcher 120 is the middle scope in the lineup of Chinese-sourced
achromats that includes the smaller C102HD, and the larger CR150 (both
sold by Celestron.) Regular readers of this web site know that I think
these inexpensive refractors offer excellent value for the money, and are
generally very good performers.
I've seen quite a few of these 120 mm f/8.3 refractors. They're sold under
various names, including "Skywatcher" (the one I bought) "Orion Skywatcher"
(same unit but with a white tube and accessories, including an equatorial
mount) and "Bresser" (black tube, sold in Europe.) As of this writing, there
is no "Celestron" version of this model.
The Skywatcher 120
"Orion" version has a white tube
The telescope offers no surprises optically. In fact, you could piece
together your own review of this scope by reading my previous comments
about the C102HD and the CR150, and mentally averaging them. The
optics are good. Mine is slightly undercorrected (about 1/4 wave+) and
has a minor zone in it.
Others I've seen are very good optically also. I spent time at Astrofest
'99 with one, looking at Jupiter and Saturn, and I liked what I saw. There
is some false color around bright objects like Jupiter and Vega, but it's
not as bad as on the 6" CR150. During moments of good seeing, impressive
detail was glimpsed on Saturn.
I spent a couple of evenings with mine, comparing its views to the TV102
and a NexStar 5. The Skywatcher threw up the brightest image of the three;
the difference was not subtle. 4.7" of unobstructed aperture is a lot more
than you might think. It was competitive with the expensive TeleVue at low
powers, but as the magnification increased, the apo pulled out further and
On bright objects, it's obvious the Skywatcher isn't an apo - bright stars
are a little "yellowish" with the trademark purple halo around them. But
it isn't too bad, and you can always resort to #8 or #12 yellow filters
to tame the purple tint.
The equatorial mount offered by the Orion and Bresser versions of this
scope is adequate for visual use, but as the powers climb, it gets a little
shaky. Some retailers sell the scope on the alt-az AZ3 (pictured) which
I think is woefully undersized for such a long tube. The AZ3 places all
its mechanical stress in the altitude axis upon one 12 mm metric screw,
which never seems to be at the right tension. It was maddening to use.
If you get an AZ3, I'd keep its load to a Short Tube, Ranger/Pronto class
Like the C102HD and the CR150, the Skywatcher 120 offers good optics,
and is a decent value for the money. Recommended.
2) Celestron C 9.25 8/7/00
(9.25" f/10 SCT, generic EQ mount, 25 mm eyepiece, 6X30 finder,
about $1200 for OTA, about $1300 with mount.)
This telescope has garnered cult-like reputation amoung Schmidt Cassegrain
aficionados. Rumor on the street has it that these scopes receive a lot
more attention at the factory than Celestron's other SCTs. The primary is
said to be a paraboloid (as opposed to the aspherical figures on most SCTs)
with a slightly longer f/ ratio than is usual for this type of scope (this places
less optical strain on the secondary, which does not have to magnify the image
as much). Celestron doesn't advertise them much, and the price seems really
low for what you get.
The Schmidt Cassegrain for people
who hate Schmidt Cassegrains:
Celestron's C 9.25
In photos, the tube looks pretty much the same as your standard-issue C8 OTAs,
but in reality they're bigger, heavier (25 lbs) and longer. You'd never mistake
one for a C8. The OTA balances on a Losmandy-compatible dovetail that rides
the entire length of the underside of the tube.
I've seen a number of these in the past couple of years. Based on my experiences,
I would have to say, yes, there does appear to be something special about these
C 9.25s. Like the others I've seen, the sample pictured above throws up a near-
perfect star test. Its contrast and sharpness are really impressive - not just for
a Schmidt Cassegrain, but by any objective measure. These C 9.25s also seem
to have a lot less image shift than in your usual SCT. One sample I saw - the
one belonging to Todd Gross - is a stunner.
There's a nifty three-digit mechanical counter near the focuser, which should
help your photography/CCD efforts (newer units no longer have the counter.)
The tube assembly is only $1200. The G9, which adds an equatorial mount,
is curiously priced at only $100 more. Placing a load the size of a C 9.25 on
top of a generic Chinese mount may amount to cruel and unusual punishment
in some states, but hey - you need an extra mount anyway, and it's only 100
bucks extra, so why not go for it?
For serious use, however, you should get a Losmandy GM8 or better. Interestingly,
Celestron once did offer the C 9.25 on a slightly-modified version of Losmandy's
excellent GM8 mount, but they were discontinued after a short time. If you can
find one of these on the used market, consider yourself lucky.
The C 9.25 is the Schmidt-Cassegrain for people who think they hate Schmidt-
Cassegrains. Highly recommended.
3) Pentax 75 SDHF 8/7/00
(75 mm f/ 6.7 air-spaced doublet with field flattener lens, OTA only, about $1450 street)
Pentax refractors are not officially available in the US, but they do show up
from time to time on the used market. They appear to be very popular in Japan.
This cutie offers some really nice performance for such a small, light instrument.
A Real Cutie: The Pentax 75 SDHF
All of the Pentax refractors in this line (the 75, the 105, and the 125) employ
an unusual design - there's a doublet up front, and a single-lens field flattener
near the focuser. It's like 3/4 of a TeleVue 101. These field-flatteners usually
screw up the image a bit, but this one star tests really well - just a little
spherical aberration, and some very slight false color. The contrast is impressive
also, with very little glare (I tried to induce some while looking at the moon.)
You'd swear you were looking through a well-baffled apochromatic doublet.
Optically, the scope is much better than a Ranger/Pronto, but it falls a tad
behind the Takahashi FC76/FS78. We spent an enjoyable evening looking at
the summer Messier objects. One nice highlight was looking at M8 and M20
in a 19 mm Panoptic with an OIII filter attached. Aggressive filters like the
OIII aren't usually recommended on small-aperture scopes like this one, but
the Pentax look it in stride, and revealed impressive extension on the nebulae.
Low contrast objects like M33 and M101 were easily seen, an indication that
the field flattener was relatively benign. The Double Cluster was an impressive
Mechanically, the scope is better built than the Vixen units, but not quite
to the artful level of a Takahashi. Like many Japanese telescopes, this one
came equipped for .965" eyepieces. Luckily though, there was a 2" adapter
included. You may have trouble finding focus with a 2" diagonal in place
unless you have a low-profile 2"-1.25" adapter like the Astro-Physics or the
JMI (hint: the TeleVue is too high, and the Orion unit is just barely so.)
The dew shield is retractable and has a rubberized ring at its tip - nice touches.
The scope is really light, around 4.5 lbs. The tube ring is tapped for 1/4" X 20,
which means you can mount it on a photo tripod. The (Japanese-only) manual
suggests that you could really go to town on accessories if you had a mind to.
The only kicker with this nice little telescope is that, here in the US, there seem
to be plenty of Takahashi FC76s floating around in the used market, for roughly
the same amount of money. The Taks are slightly superior, both mechanically
and optically. But they are also a lot larger. The Pentax may be the telescope
you want if you travel with your equipment a lot.
Recommended for devotees of the Pentax marque, or for gap-filling in larger
4) Takahashi FS152 8/23/00
(6" f/8 air-spaced doublet fluorite apochromat, OTA only, $10,800 list,
about $9000 street)
Coming Soon: Astro-Physics AP155/ Takahashi FS152 Comparo
Here's a telescope commonly mentioned in the "If I only had enough money"
category. The FS152 is the largest and most ambitious telescope in Takahashi's
standard line of fluorite refractors. There are the triplet-based FCT150 and
FCT200, but these are out of the reach of most amateurs.
His Royal Coolness: The FS152
For those of you used to looking at FC76s and FS102s, the FS152 is going to
come as a visual shock. It looks like an FC100 that took a few too many
steroids. The OTA weighs in at around 24 lbs, but due to the long length of
the tube - about 52 inches - you will need something on the order of a G11,
an AP600, or Takahashi's own EM200 (or better.) The 4" focuser is massive,
and the green highlights exude coolness. The build quality is typical Takahashi:
beautiful, functional, and with an air of overkill. Visually, it's a stunner.
The scope was used over several clear nights in mid-August and we wound up
throwing all sorts of telescopes against it, including the AP155, Zambuto-
equipped 7" and 10" Starmasters, a Traveler, a TV102, and a Genesis.
The star test was very good, but we did notice a trace of undercorrection and
some minor false color on very bright objects like Vega. One observer was
bothered by this trace of color. He pointed out that at this price level, you
have the right to expect color-free performance. He may have a point. Similarly,
another observer thought the amount of spherical aberration was a little too
high for a scope at this price level. As a reference, this FS152 has a little
more color than the AP triplets (which look perfectly "white" in comparison)
and about the same (or very slightly more) amount as the FS102/FC100 duo.
The figure on the objective was exceptionally smooth. The FS152 yields
impressive contrast. The more I look through these premium refractors, the
more convinced I am that nothing on the market today rivals the contrast of
these Takahashi fluorite doublets. Look at the moon and you will see a stark
white limb against an inky-black background - no glare, no halos, no light
Detail on the focuser
The focsuer was not as smooth as other Takahashi focusers I have used in the
past. It binds a bit and has a stiff motion. This came as a bit of a shock;
Tak focusers are legendary in this business. As I am accustomed to taking
apart these focusers, I disassembled it and tried to alleviate the pressure,
but I could not quite get that buttery-smooth Takahashi "feel" that I know
and love. I also noticed the design of the 4" focuser is different than the
2" units I've come to know so well.
We split a number of summer doubles of increasing difficulty. The atmosphere
gave out around Otto Struve 403 in Cygnus, a .8 arc-second pair, which was
cleanly split with clear black space in between the components. We tried several
times to split Tau Cygni and the B component of Gamma Andromedae, but the
seeing conditions did not support .5 arc-second work on the nights we had it
Even more impressively, running a limiting magnitude test, the FS152 penetrated
all the way down to 14.5 (many texts list the limiting magnitude of around 13.7
for a 6" telescope.) On deep sky, the FS152 is a real crowd-pleaser on familiar
objects like M13, M27, M11, and M42.
Saturn was razor-sharp, with Cassini's division visible all the way around the
planet virtually all the time. In times of good seeing, both the FS152 and the
AP155 completely manhandled the 4" apos - it wasn't even close. Four inch
apochromats are wonderful instruments to own (I've owned several) but they
simply don't play in this league. Jupiter revealed a dozen belts or more in
vivid detail and contrast.
Of the scopes we tested alongside the FS152, only the Starmasters and the
AP155 were in the same league. Seeing conditions did always support the 10"
EL all the time, and the 7" was a little dimmer. But the Zambuto mirrors showed
everyone that you don't need a refractor and a five-digit disposable bank balance
to get pinpoint, contrasty views. The most seriously consistent challenge came
in the form of the AP155. I am working on the article describing the comparison.
One factor that emerged was that the Takahashi had superior contrast, but the
Astro-Physics had better color correction. But which one did we prefer? Keep
checking back for the article!
The massive dew shield. Note the collimation
screws on the back of the lens cell, a nice touch
No writeup of this telescope is complete without mention of its price. $10,000+
is a lot of money for an optical tube, no matter how you slice it. When you add
the mandatory mount, finder(s), diagonal, etc, you might be pushing $15K or even
$20K. I am forever cautioning readers to personally audition telescopes before
purchase, but since these FS152s are as rare as hen's teeth, this will not be
possible for the majority of readers. The best I can say to prospective buyers
is to evaluate your needs and budget carefully, and act accordingly.
The FS152 is a "statement" product if I've ever seen one, and is easily one of
the half dozen or so best telescopes I have ever seen. It costs much more than
the AP155, and is perhaps a half-step behind in performance as well, but at least
you can get one (the waiting lists for AP refractors suggests you will now wait
years for one.) I hope you are lucky enough to look through either one someday.
5) AP180 EDT 9/6/00
(7" f/9 apochromat, NLA, OTA only)
Want reviews of rare, exotic telescopes? You've come to the right place!
I'll put up some quick comments on this one in case some intrepid astronomer
runs across one on the used market. A very small number of these were made
about ten years ago. The design is pre-Starfire, so it is one generation
removed from the current models. Astro-Physics also made an AP180 EDF
f/7 version for a short time.
If I showed you all of this stuff, I'd have to kill
you. The AP180, center, on the Meade LXD750.
Other scopes: FS152, AP Star12, Starmaster 10" EL,
Genesis, 20" Obsession, AP155 on AP900 mount,
Traveler. "Ted" is holding Celestron Pro 7X50s
I had this one on loan from a club member for about a week. It was mounted
on the Meade LXD750. The tube diameter of the AP180 matches that of the
Meade 178ED, so all you 178ED owners can rest easy when you run across
these 7" APs - you won't have to buy any extra rings...
This sample has modest undercorrection and is impressively color-free. I
did a brief Messier tour through the summer sky. The sharpness and contrast
are superb (what did you expect?) but I feel the newer Starfires, particularly
the mighty AP155, are even better. It has a level of polish and finesse, both
optically and mechanically, that this AP180 doesn't quite match.
I noticed no color, even when the scope was pushed to 500X+. The limiting
magnitude was an impressive 14.9. Doubles were split down to the .8 arc-
second level. Familiar objects like the Ring, the Dumbbell, and the Veil
were exciting to look at. I'd tell you about the scope's planetary perform-
ance, but I am absolutely dead tired from staying up all night doing these
reviews lately, so the scope went back to its owner without me having
looked at Saturn or Jupiter through it. I may report back later if/when
I see it again.
It is hard to believe you could once buy this telescope for $4595 (1992).
I would not venture to guess what they are going for on the used market.
If you're dying to get one, I'd suggest putting your name on the waiting
list for an AP155 instead, which in the end is a slightly better telescope.
I should stress again that these AP180s are extremely rare. But if you
run across one of these at a reasonable price, you know what to do.
6) Orion Executive Brass Mini Telescope 9/11/00
(25 mm achromat, table-top stand, 3 eyepieces, $69.95)
All I'd known about this telescope was that Orion advertised it for years
near the back of the catalog, and that it came with a 'red silk' lined gift
box. You know something's up when they advertise the packaging. A
friend of mine bought one a couple of years ago and called to tell me.
Red Silk, and Orion Executive
Brass Mini Telescope
"Ed, I just got the Orion Brass Mini Scope."
"Does it really come with red silk??" I asked.
"Uh...yeah, I guess. It's pretty cool, actually. It comes with three little
eyepieces labeled '30X', '20X', and '15X'."
"And the red silk?" I said. "Is it really everything they say it is??"
So finally I broke down and ordered one. It is pretty cool, as my friend
said. The three eyepieces don't match any barrel diameter I know and are
of unspecified design (judging from their field of view and eye relief, I'd guess
they're Ramsdens or Huygenians.) The construction is probably better than it
has to be, and the focuser is decent. The alt-az mount is rough (especially
in altitude) and it's hard to find anything with the 30X eyepiece installed.
I actually spent time with the scope, trying to find things with the 15X
eyepiece. The scope has a lot of false color on the moon, and sharpness
drops off rapidly as you leave the center of the FOV. I found M13, the
Dumbbell, and (I think) M15 (it was hard to tell, the views through this
thing are REALLY dim.) If you need to know how the star test turned out,
we need to have a talk.
It's not a serious astronomical telescope. It looks nice sitting in the den.
And yes, the red silk is real.
End Telescope Reviews, Page 13