Sunday, January 03, 2016
Goodbye Betsy, Hello Hermione...
2015 was a year of changes for me. Not the least of
which is one you may be aware of if you are a Facebook friend of mine: I sold
Old Betsy; she is gone. Yes, the Dobsonian that’s been at my side as my
faithful companion for the last twenty-one years has gone to live with new
owners, a young local couple. Never thought that would happen, did you? Neither
did I, neither did I.
I won’t wax nostalgic about all the fun Bets and I had and
all the star parties we went to over the last two decades. No point in that. It
was time. Far worse than letting go of my 12-inch Dobsonian would have been letting
her sit out in my shop and rot. I was simply not using her,
you see. What finally impelled me to say goodbye was realizing she had not had
any significant time under the stars since November 2014. I decided I’d be happier with the telescope in a new
home where she’d be loved and used.
I didn’t give
Betsy away. I sold her for a reasonable price but fair price and found
myself with sufficient cash in hand to finance a new telescope. While, yes, I
am reducing the head-count here—I’ve also gotten rid of two C8s so far—that
didn’t mean I wouldn’t consider adding a new one. It would just have to be a
telescope that fit in with my current interests, prime-focus DSLR imaging and casual
visual observing. Most of all, it would have to be a scope I would actually use.
It surprises some people to learn I am a refractor-phile.
Yes, I’ve long been known as “Mr. SCT,” in part because I have written two
books and more than a few magazine articles about Schmidt Cassegrains. However,
over the last decade or so refractors have easily become my second most used
and loved telescope, and today are not far behind SCTs in my telescope
pantheon—if they are behind SCTs at all.
Refractors are just so easy, especially for astrophotography.
Sharp images, little cool-down time, no fussing with mirror flop or focus shift, moderate focal
length. There is no doubt they produce beautiful visual images, too. I won’t
bore you with a paen to the TINY STARS a good refractor can present, even at
high power. I’ll just say that for me (and maybe for you, too, if you reach way
down into your soul) there is just
something special about lens scopes.
So, yes, I’d come to love refractors, and had some good ones for both imaging and for visual use, but what I didn’t have was a big
one, which in refractor speak is a 5 or 6-inch. While my 3 and 4-inchers can do
well for imaging, there’s no doubt a 5 or 6 will pull in more stars, and that
for visual a 5-inch refractor is where things start getting interesting.
So which would it be? A 5-inch or a 6-inch? I soon decided
against a 6-inch. If possible, I wanted to stay within the modest budget
provided by the sale of Betsy. Getting an ED/APO sixer would have meant
tripling that at least. Sure, I could have gone “achromat,” but the major reason
for doing so would have been bragging rights, being able to say I had a 6-inch refractor.
The ground truth is that a good ED 5-inch can beat one of today’s affordable achromats at most things. Certainly, imaging and image processing would be complicated by the chromatic aberration inherent in fast (f/6 - f/8) achromats. Also, while a 6-inch would have been OK on my CGEM mount, I thought a 5-inch would be better. And I thought a 5-inch would also be more than usable, for visual at least, on my Celestron VX GEM.
The ground truth is that a good ED 5-inch can beat one of today’s affordable achromats at most things. Certainly, imaging and image processing would be complicated by the chromatic aberration inherent in fast (f/6 - f/8) achromats. Also, while a 6-inch would have been OK on my CGEM mount, I thought a 5-inch would be better. And I thought a 5-inch would also be more than usable, for visual at least, on my Celestron VX GEM.
And so the hunt for a
5-inch APO began…
I ruled out the Astro-Physics and Takahashi refractors from
the get-go. Beautiful scopes and wonderful performers, sure, but costing so
much more than what my budget, even stretched to the breaking point, would
allow as to not even be funny. I was also uncertain I’d live long enough to
receive an AP130 given the notorious waiting times for that fine instrument.
I know better than to scrimp when it comes to quality,
however. I wouldn’t be penny wise and pound foolish. I gave due consideration
to the next tier down, the 5-inch aperture range telescopes from TEC and
Stellarvue and William Optics. I was especially attracted to the WO FLT-132 and the StellarVue 130. Both would bust my poor budget, but not
nearly to the extent of an AP or Tak, and both were beautiful and highly
regarded. What if there were a way I could get a 5-inch more attuned to my
modest means without sacrificing optical quality, though?
Perhaps the biggest recent change in the refractor scene, an
almost revolutionary change, has been the appearance of reasonably priced
5-inch ED/APO scopes in the 1500 – 2000-dollar range. Yes, you read that right,
2K or less. The two leaders in this arena so far have been Explore Scientific
with its JOC produced scopes and SkyWatcher with its Synta-made refractors. I
began researching two candidates, the Explore Scientific ES 127ED, and the
SkyWatcher Pro ED 120.
I eliminated one scope immediately. Explore sells their
5-inch refractor in two variants. The "Essentials" version is furnished with a white aluminum tube and looks a lot like the ES achromats. The other, the premium 127, uses
the same optics, an ED triplet, but in an attractive carbon fiber OTA.
I didn’t think carbon fiber was a necessity given our usually balmy wintertime
temps, so despite its good looks I passed on the carbon fiber ES.
The other contender was the SkyWatcher Pro ED 120. At first, I was
a little hesitant to give up 7mm and live with “almost” 5-inches, but much as I
liked the ES scopes, I gradually began to turn more to the SkyWatcher. While
the objective on the SW is a doublet rather than a triplet, one of its elements
is of FPL-53, synthetic fluorite if you will, and all the reports I read said the
telescope’s color correction was every bit as good as the ES’ triplet, and
maybe even slightly better.
The more I researched, the more I came to believe the
SkyWatcher was the scope for me. Not only were the optics (reputedly designed
by a Takahashi refugee) admired, the scope came with considerable lagniappe compared to the ES. In
addition to the OTA, the SkyWatcher package included a 50mm RACI finder, a pair
of eyepieces, a 2-inch star diagonal, and, most of all, an aluminum case. The
current ES packages seem to lack all these things.
There were plenty of finders and eyepieces and diagonals
around here, but the case was a pretty big deal. For a refractor to live up to
its ultra-portable reputation, it really needs a good case to protect it and
keep it and its components organized, and it would be nice not to have to shell
out more bucks for one.
In all my reading and asking around about the SkyWatcher, I
only uncovered one thing about the scope that was routinely criticized: the
focuser. While most users rated the standard Synta Crayford as useable, there
was no pretending, I gathered, that it was within a country mile of a Moonlite
or Feathertouch. That was OK. Given the amazing price of the Pro ED 120, which
was on sale at Christmas for freaking $1399.00, I figured I’d be able to
replace the focuser with a Moonlite if I had to. So the SkyWatcher it was. I
grudgingly gave up my credit card number and spent a week in anxious waiting
for the new baby to arrive.
The Unboxing…
The coming of the new scope was actually rather anticlimactic
as such things sometimes go. I was surprised at how heavy the box was
and half dragged-half carried it into the sun-room where I do my telescope
unboxing. I was slightly disturbed at the sizable gouge in the box, but that
turned out just to be in the outer carton and the telescope’s aluminum case was completely
unharmed. Kudos to SkyWatcher for doing a good job packaging wise. Anyhoo, with
the new kid out of her box, my impressions were, in no particular order:
· A pretty thing. I must admit I prefer all-white telescopes, but the 120’s black/bronzish metal-flake tube and white trim is striking.
· The focuser seemed OK. Stiffer than I like, perhaps, but smooth. And the smooth and easy fine-focus control made up for any stiffness in the course focus. One big plus was the wide focus range. I found I could rack this Crayford out far enough that I would not need an additional extension tube to bring a camera to focus with a standard prime focus adapter or field flattener.
· Beautiful objective lens with faint greenish looking coatings. Very good coatings, I thought, since the objective seemed to disappear when I looked down the tube, even in fairly bright light.
· Decent accessories. The included 2-inch diagonal looked good. Metal and hefty. The two 60-degree AFOV eyepieces, a 20mm and a 5mm? OK, and at least a modest upgrade compared to the “free” Plössls you usually get with telescopes these days. The 50mm finder was also fine, if not any different from what we are accustomed to seeing from China these days. The case was excellent, I thought. Not strong enough to ship the scope in, no, but more than good enough for hauling the 120 to star parties in the back of my 4Runner.
· Tube rings and (Vixen format) dovetail? I’d have preferred the better rings furnished with SkyWatcher’s up-market triplet APOs, the Espirits. The 120’s tube rings are standard Synta. I believed they would do the job, but they were certainly not as pretty as those that come with the more expensive scopes. On the other hand, the dovetail was nicer than what I usually see on Syntas. Given the light weight of the OTA, I was pretty sure I would be able to use it and not have to upgrade to a Losmandy “D” setup.
First Light…
At mid-afternoon, the sky was not looking good, no, not good at all, which wasn’t
a surprise given the sort of weather we’d had over the past month. But as the day wound down it suddenly became apparent there would be some clearing. By sundown, the sky overhead was looking better and better, though glancing at the
horizon showed more bad-stuff clearly on the way. Speed was clearly of the
essence, so I didn’t fool with the CGEM, assembling the VX instead.
Even before aligning the VX, I could tell the mount was
going to be happy with the refractor. While the longer tube of this 11.3-pound OTA maybe put a little more stress on the GEM than my 14-pound Edge 800 with its short tube does,
it was clearly not more than the VX could handle. It only took one 11-pound
Synta pancake weight to balance the mount with the, 2-inch diagonal, and one of
my (heavy) Ethos eyepieces.
With clouds beginning to flow back in as astronomical twilight came on, I
didn’t waste time doing a precise polar alignment. Sighted Polaris in the
hollow polar bore, did a 2+4 goto alignment, and we were off to the races with
our first light object. Which was? Vega. No point in delaying; I wanted to know
from the start what the excess color situation would be with this big
refractor. What I saw was truly astounding:
in focus Vega was a pure white. On either side of focus, there was a
tinge, but just a faint tinge of color. In focus, nada, zip, zilch. Hooray!
How was the mount’s operation with the refractor onboard? Even
with the legs extended about 75% to allow me to comfortably view objects
overhead (while seated in my observing chair), the shakes were minimal. Goto
operation was normal with no hesitation of funky sounds from the mount. For
visual, at least, the VX plus the Pro 120ED is a fine combo.
That was almost all I was able to accomplish on night one.
Oh, I did scope out M15, M37, NGC 457, and a few other bright objects as haze
and clouds built. How did they look? Pretty putrid in the poor conditions, but they
still looked like star clusters should
look in a good refractor: tiny stars even at 200x. How was field flatness? At
f/7.5, very good. My higher quality eyepieces presented beautiful views field
edge to field edge, and even my old Happy Hand Grenade 16mm Zhumell 100-degree
did a reasonable job, similar to what it does in the Edge 800.
I was hoping to get a look at M42 on this first light night,
but that was clearly not going to happen. It was obvious that by the time it
was above the trees to the east we’d be completely socked in again. There was time for one more
test. I inserted a heavyweight eyepiece, my 35mm Panoptic, sent the scope to an
object nearly at the zenith, and did some experimenting with the focuser.
Not too bad, but
there was some slippage with the big ocular. It was clear I’d need to adjust
the Crayford if it were to handle my DSLRs and field flattener. That would be
in the morning, though. The stars were winking out now, and I called it a
night. I left the mount out in the yard (covered), but I brought the 120
inside. I just couldn’t bear to leave beautiful new baby out in the yard all by
herself.
Adjusting the focuser proved to be fairly simple. Next
morning, I mounted the OTA back on the VX, installed my Canon 400D and Hotech field flattener, and pointed the scope to
the zenith. Using instructions I found on the Internet, I adjusted one hex
screw on the focuser until the Crayford held the load of the DSLR and flattener
with no slipping, but remained reasonably easy to focus with the coarse control.
The Naming of Telescopes…
Sometimes you do get thrown a
bone. The Saturday night after receiving the 120, the Moon was old and the
clouds were gone for a while. I headed to our club dark observing site about
30-minutes to the west. It’s not pitch black dark, but the Milky Way is easy on
any halfway decent night and I thought that if the weather held I might have a
chance to see what the new telescope could really do.
I actually did get that chance, though my two fellow club members, Taras and Ken, and I were only given a little over
two hours of good conditions. The Milky Way was visible, but only faintly visible and then
only for the first hour of darkness. Still, that was enough time for the new girl, again set up on the VX—this would be a purely
visual night—to show her mettle.
First object after astronomical
twilight was the great globular cluster in Aquarius, M2. In my opinion, this
beauty is one of the most overlooked globs in the sky. Maybe because it’s a
trifle low for our northern brothers and sisters. All I know was that it was a
wonder in the refractor, even at 30x, and the more I increased the
magnification, the better it looked.
That was pretty much the story with
everything I observed. Very similar, all in all, to what I’d have seen in an
8-inch, but with that refractor zip
added. What didn’t I get to try? The Moon or a planet. The Moon didn’t rise
till long after the clouds intruded, and there were no evening planets on hand.
Given the way the scope handles bright stars, however, I have little doubt she will be
good on the Solar System.
Most surprising DSO of the night?
Had to be the Helix Nebula. I wasn’t expecting a heck of a lot out of NGC 7293.
The big planetary was low and on the outskirts of the Mobile, Alabama
light-dome. I sent the VX that way anyway, inserting my 30mm “finding”
eyepiece, an el-cheapo GSO that came with my 10-inch Dobsonian. Why I did that,
I don’t know. Such a low power, 30x, would surely render the big nebula invisible
in the sky glow.
Nope. Even at that low magnification
and with the resulting bright background, the nebula was still visible as a round spot
at field center. That is testament, I think, to the superior contrast
characteristics of a good refractor. I didn’t mess around at low power long,
replacing the 30mm with my 13mm Ethos and affixing an OIII filter to that.
At 70x, the Helix was starkly visible.
While the donut hole was not easy, it was there. Bumping up to 112X with the
8mm Ethos further improved the view, and, as I continued to stare, I began to
pick up the arc of nebulosity outside the main annulus. What it reminded me of
was the way the Helix looked with a C8/OIII years ago at the old Deep South
Regional Star Gaze at Percy Quin State Park near McComb, Mississippi, where
the skies were considerably better than what I had on this night. All I knew
was that what I was seeing was marvelous, and proved to me that a 5-inch
refractor can be a satisfying visual instrument for the deep sky.
So it went for a while longer,
till haze began to drift in in advance of the next storm front and we
called it. I was just thrilled. The views provided by the new scope were
everything I’d hoped for. The concern I’d had about the focuser had also
evaporated. Oh, someday I may still replace it with a Moonlite, but over the
course of the evening I didn’t have any problems with it and didn’t even give
it any thought—it just worked.
Only one thing was left. The
naming. While I have often told you, dear readers, that you should look upon
telescopes as tools, there is no
denying I don’t always practice what I preach. In spite of myself, my telescopes
inevitably become more than just tools. They become my friends with individual quirks and personalities, and I have to
give them names. At the end of this evening, the SkyWatcher's name was
obvious; I didn’t even have to think about it. Folks, meet Hermione (Granger).
“Herminone” because she is clearly magic.
The Final Test…
There was no doubt after my dark
site run that Hermione would get some use as a visual scope, but that was not
why I bought her. I have an excellent 10-inch Dobbie for visual. The main impetus
behind acquiring a 5-inch APO was to have an imaging scope with a little more
aperture and focal length than my smaller APOs, but less focal length than my
Edge 800 (which comes in at 1400 mm with a reducer). So, I wanted to give Miss
H. a clean bill of health imaging-wise as soon as possible. That happened just
as the Moon was coming back into the sky, but before the wave of pre-Christmas
storms that are still plaguing the Gulf Coast began to roll through.
Actually, I had little doubt Hermione
acquit herself well for imaging. My main concern was with the whole package, scope
and CGEM. I had yet to try to auto-guide the Celestron mount in the months since I got her. The main reason for that being the terrible summer and autumn weather, of course. It’s been bad, and the two major imaging expeditions I did
this year, one to the Deep South Regional Star Gaze, and one to the Peach State
Star Gaze, involved targets well suited to my 80mm APO, which is just fine on
the VX—a lot easier to haul around than a CGEM.
Wouldn’t you know it, though? By
the time the mount and Hermione were set up (I used an ADM Vixen-to-Losmandy
adapter to get the 120 on the CGEM), the sky was going south again. That meant I was not able to spend any time tweaking
the settings in PHD2. I went with the stock settings in the brain icon, firing
off 20 2-minute exposures of M15. I believe I could have gone longer than
2-minutes per sub with PHD2, but the background was bright enough in 120-second
frames that I didn’t dare expose longer. Building haze was making my normal light
pollution worse, scattering the glow from the subdivision’s countless Christmas
lights till the sky was a near Technicolor mess. At any rate, the stars were
perfectly round in every sub. The only ones I threw out were a few where
drifting clouds had passed through the field.
My thoughts on the results shown
here? Darned good considering the conditions. If I ever get another clear
night, I’ll tweak PHD2, but given my modest requirements, I’d say guiding was
good enough as is. Certainly it was a lot easier to image with the refractor
than with my focal-reduced C8. Any light pollution induced gradients were minor
and not like the “porthole” effect I get with the Edge and its f/7 reducer
under these conditions. While the Edge displays minimal focus shift, it was
also nice to be using a scope with none.
What’s next other than tuning up
PHD2 a little in the backyard? Some dark-site imaging time should el Niño have
mercy on me. Accessories? Now that I have resolved to continue with the stock
focuser, for a while, anyway, I might
consider the SkyWatcher .8x reducer/flattener. However, at this time, I’m
pretty happy with the image scale the scope produces at f/7.5. A little faster
would be nice, sure, but “a little faster” would mean “a little smaller” in the
frame, and 900mm is well suited to the sorts of objects I photograph. If I need
more field, there is always one of my smaller APOs, and flattening wise, the Hotech
is doing one heck of a job.
Will I miss Betsy sometimes? I
will. Mostly because of the wonderful memories. But I still have those
memories, and I still have my C11, Bertha, and Zelda, my 10-inch Zhumell
Dobsonian, who is a lot easier to handle than Bets ever was. As for the vaunted
Hermione Granger? I believe this is the beginning of a beautiful friendship.
Comments:
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Looks like a success to me, although 21 years is a long run with a trusty telescope i'm sure you'll have many more with the new one
Are you using a StarSense on your new Refractor? You do realise your refractor is 4.7" and not 5"?
Dave Aucoin
Dave Aucoin
Yes I am using a StarSense, Dave. And yes, I did figure out that 120mm is a few millimeters short of 5 inches. That's why I said I decided to settle for "a little less than 5-inches." ;)
Hi Rod,
I have the 100 mm Pro ED on backorder since December, supposedly due in mid-February. We'll see. Since I already have a 12.5 Truss, and an older 6" f/8 Astrophysics (mid-1980s), I wanted a 4" class refractor for quick trips outdoors. Also, I bought it with the 2017 eclipse in mind, since that trip will hopefully involve dark moon stargazing somewhere in the vicinity of the eclipse path, but with the need for “rapid deployment” should clouds have to be dodged. (Also, couldn't pass up the sale...) Enjoy your 120!
John O'Hara
NW Pennsylvania
I have the 100 mm Pro ED on backorder since December, supposedly due in mid-February. We'll see. Since I already have a 12.5 Truss, and an older 6" f/8 Astrophysics (mid-1980s), I wanted a 4" class refractor for quick trips outdoors. Also, I bought it with the 2017 eclipse in mind, since that trip will hopefully involve dark moon stargazing somewhere in the vicinity of the eclipse path, but with the need for “rapid deployment” should clouds have to be dodged. (Also, couldn't pass up the sale...) Enjoy your 120!
John O'Hara
NW Pennsylvania
# posted by 
: 2:00 PM
: 2:00 PM
I'm interested in the 120 but noticed from forums that you can't collimate the objective like you can with the ES 127 scope. Do you see that as a problem? I'm assuming that if i check out the collimation when I get it, and send it back if it's our, then I shouldn't have to worry about it any more, assuming I don't drop kick it during transportation to and from the field! Your thoughts?
I don't think so. Quite robust mechanically, and I haven't heard anyone having problems with collimation.
Has it really been almost two years? Anyway, yes, I still love her. She is set up in the backard e'en as we speak. :)
Just got one of these in Pensacola. Gentleman from Texas was selling it and heading to Fairhope to see his mother, delivered it to my house, it just doesn't get any easier. I'll keep and use my C8 forever, it's been with me for 40 years and now that it has autographs from Jonathan Frakes and Jeffrey Combs on it from Pensacon (Yeah, I carried it into the civic center for that...can you blame me?) I have no reason to ever part with it. I've been considering one of these 120 Pro ED's for years for much the same reason as you, it just all finally came together this past week. It'll ride a CG5 for outreach and CGEM for photos, just like the C8. My ST120 and C8N are soon to be shed, I figure I've got the two scopes to take me into my twilight, along with the Lunt 60Ha I couldn't resist last week either. Be ready for horrible weather on the Redneck Riviera for a while.
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