So, persistent cloud cover at night and terrible seeing
conditions during the day have laid waste to any plans I have had for any
sketching. A couple of nights things
cleared up around midnight, and of course I’m headed to bed… and then a couple
of hours later it starts raining…
Oh, well, part of the deal with astronomy….
With this spell of poor astro weather, I’ve decided to look
over the gear that I have. Maybe move on
some of it, and consider any things that may help. Why I have the scopes that I have (too
many…), and the bits and pieces that go with them, like eyepieces. As eyepiece design needs to be matched to the
telescope being used (all to do with matching focal plane shapes produced by
telescopes), I’ll see if there are any eyepieces that I just don’t use enough,
and find new homes for them.
There is no such thing as a “perfect telescope”. Too many different functions are at
play. A really big aperture is nice for
seeing the arms of spiral galaxies, but totally useless to see the wonderful
network of dark nebulosity seen through the Milky Way, where binoculars or a
rich field scope provides. And while a
big aperture can provide high magnification, it is also more suceppetible to
the effects of atmospheric turbulence than a smaller aperture. There is a trade-off always somewhere. So a lot of people have a few scopes to cover
different aspects of interest they have.
I’m no different, and may I confess, probably a scope tragic too…
Odessius: my 17.5” f/4.5 cannon. When I got this scope, it was configured as
its original Coulter Optics Odyssey II SonoTube form. Coulter made big aperture scopes affordable
for amateurs in the 1980’s. From 8” bubs
through to a 29” monster that I drooled over ads in astro magazines. And their mirrors were generally very
good. And for the time, these
instruments were what defined “portability” in big apertures. With hind sight, these were a nightmare to
move around – my Odyssey II OTA occupied the entire passenger side length of my
Mazda Tribute, from the front seat to the rear gate! And the mount was a disaster. But like I said, it was the best for its
time.
When I got this scope from an old fellow astronomer, while
the OTA and mount wasn’t much, the optics were just fine, and the primary
mirror had been recoated only a year before.
When I got it home, the first thing I looked at was M42, and WOW! I saw filaments of pink, blue and green in
it!!! Alas today I no longer can see
these colours as my eyes have changed since then.
I got this scope with the thought of re-purposing the optics
into a collapsible instrument. The
result was Odessius. I was inspired by
Albert Highe’s tri-strut 17.5” scope, and I fashioned my scope with my own take
on things. And Odessius is a joy to use.
Kulali: This is my 8” f/4 compact travel scope. Crafted by me, I can have this little scope
sit on its own tripod, or coupled to an equatorial platform.
Kulali is my big aperture rich field scope. With the right eyepiece, I can get a tick
over 3° true field of view – the ENTIRE circle of the Veil Nebula fits in
this! Magnificent! Kulali is one of a couple or rich field
scopes that I have.
F4: This is my grab ‘n’ go scope at home. I built this 8” f/4 (see where I got its name
from???) with a good mate of mine. The
tube came complete, but without a cell for the primary, which was easy to make
one up. As this scope is always set up,
and always at hand, and very quick to cool down being a solid tube Newt., if I
see a clear sky, I use F4 to tell me how seeing conditions are for plundering
the Moon for a sketch. And of course, I
us F4 for whatever viewing I want to do at home. As an outreach scope or a scope I lend to
friends, it is wonderful as its mount sets the eyepiece at a comfortable height
while seated.
I’ve modified the mount many times, using it as a test piece
for ideas. The way I have the cradle
made up, I can quickly remove the OTA from it and place the OTA on an
equatorial mount and use the scope for video astronomy – one thing this little
gem of a scope excels at because of its big aperture and short focal length.
Orange tube C8: When I was a kid, THIS was a dream scope of
mine. One of famous advertisement in
astronomy magazines from the early 1980’s was of the late Leonard Nimoy
promoting this model telescope:
This old timer is my high magnification scope I use for the
Moon and planets. When conditions are as
good as they get, this scope’s optics allow me to push things to 400X with
magnificent resolution. Its mirrors may
not be as pristine and reflective as when new, and the corrector plate doesn’t
even have coatings (Special Starbright Coatings were an optional extra when new
at the time). Despite these
“shortcomings”, the quality of the optics is just something else. I’ve seen newer C8’s that are not up to the
same standard as this old bird.
For a long time, this was the only instrument with a clock
drive that I had. Yet even now, unless I
am doing video astronomy, this is the only clock drive scope that I use for
visual observing. The picture below is
of myself next to the C8 about to do a sketch of the Moon.
Amgab: this was first DIY telescope. This 10” f/5 scope I built with the
assistance of a friend who had access to some wonderful tools. For the design I was inspired by “A Scope
like Alice” made by Ron Ravneberg. Ron’s
two pole design reminded me of an article I had seen in a 1970’s Sky and
Telescope magazine article which described the structural mechanics of
different cantilever systems. At the
time I was also undertaking a Civil Engineering course at university and this
particular article really appealed to me.
I understand the mechanics behind
the viability of the two pole design, and coupled with Ron’s design idea, I
came up with my own take on it. I very
much believe in the Amateur Telescope Makers’:
It is sporting to lift this design or that of someone else, as long as
one adds their own unique design take on things.
Amgab was my first
big aperture scope. It led me on a path
of discovery within telescope making and innovative design. I’ve seen many wonderful things with it, and
taken it on many lovely outings, including with my family as its stowed
configuration takes up so little space. Amgab
is the acronym of my friend’s name and my own.
Refractors: I have
three refractors at the moment. I don’t
need all of them and most likely will find a new home for one. One is an ED80 that I use with my Daystar
Quark filter with the Sun. I tried out
the Quark filter with many other refractors both achromats and apochromats, and
found the good old ED80 f/7.5 to be a great match with the Quark. Another refractor is a 100mm f/5 achromats
which I use as a grab ‘n’ go rich field scope – this scope gives me up to a 5°
true field of view. The last refractor
is an 80mm f/5 achromats – I can use this for video astronomy and as a rich
field scope, but in all honesty I have other scopes that I prefer for these
same purposes. This last scope most
likely I’ll be moving on.
I do have another refractor, my very first scope, a 50mm
Tasco. I really don’t use it now, but I
keep it for sentimental reasons. I’ve
had this little thing for over 30 years now.
I first saw Saturn through it, and did my very first astro sketch using
it – of Halley’s Comet! Most recently I
used a good quality Plossl eyepiece with it instead of the poor cheap eyepieces
that came with it. I was stunned by the
quality of the image this scope through up!!!
Where previously I only saw the central bright “fan” that surrounds the
Trapezium in M42, with this good Plossl eyepiece saw lovely wispy extensions of
material, a soft faint glow of body, and even some bulk to M43 and a glow of
The Running Man, all previously invisible to my younger eyes under the darker
urban skies I had 30 years ago! I cut my
astro teeth with this little scope. I
learned a lot with it despite it being hobbled with poor eyepieces. The most important thing I learned was:
It does not matter what quality of telescope you have – what is most
important is that you have a telescope to go with your curiosity!
Marana: This is my big aperture travel scope. A friend of my said to me when they saw me
pack it up “Gee Alex, that thing just disappears into its belly button!”. A very innovative detail of this scope is
that it uses active truss elements, not passive. What’s the difference? Passive elements means that the member
components are locked into place not preloaded with any stress. Active elements means that the member
components are loaded with stresses as they are locked into place. All the components have a corresponding
element that is loaded in an opposite direction, so they all work to balance
out the system – something that I’ve picked up from my engineering
background. This way supposedly thinner
elements can be used and still produce an optically stable system. I’ve loaded Marana with a big 1kg eyepiece,
and it has maintained perfect collimation.
Takes me just a few minutes to set up, and is silky smooth to use. And yes, it is a balanced scope – ALL my
scopes are balanced, not a brake or clutch in sight, just the occasional
counter weight and the same quality of action all the time. Perfect!
114mm dobbie: Really this scope belongs to my kids. I made
a table top dobbie mount for the little scope that the kids love to use. But I every now and then commandeer the scope
for video astronomy. It is a modest
little scope, with a fast spherical mirror, so best limiting things to low
magnification, and it does very well at this.
A fun little scope to use.
So, this is my artillery selection. Too many scopes? Probably.
Will I get more? Well, one James
Bond title is “Never say never-again”…
But for now not likely… I wonder
how long the “for now” period will last…
Alex.
