ost of this stuff will be interesting only to the die-hard telescope nut.
Not that my stuff is so phenomenal, but telescope addicts are a different breed.
We'll spend hours going through
Sky & Telescope or
Astronomy magazine, searching for that last bit of information prior to ordering
a $5.39 item. We'll go to star parties and take endless rolls of photographs, each
documenting yet another angle of some piece of equipment we've already photographed
over the past 6 times we attended the same star party. We'll examine, borrow, talk,
discuss and formulate precise opinions of what we prefer in regard to items we'll
never buy...
Then again, all in all ATMs (Amateur Telescope Makers, of which group
I could barely be called a member) aren't that much diffferent from
any other group of hobby enthusiasts. It's for these folks that I've put
together this display of my modest telescopes.
10 inch; Dobsonian, homebuilt (with liberal usage of commercial components)
This scope was constructed during the fall and winter of 1991, while waiting on
the arrival of the optics. It has a 10 inch f5.51 Coulter Optics primary, with
a 1.83” Telescopics secondary mirror. After receiving an f4.5 mirror that
was mistakenly thought to be f5.6 (with a correspondlingly extreme comparator
index), I got this mirror. It seems to be good, although I've never had it tested.
After using the scope for more than 8 years and comparing what I've seen in it with
what I seen in others, I can fairly say that the images are in the upper 50 percentile,
maybe even better. There may be a slight turned edge, but nothing extreme.
However, the proof is in the pudding, and I've seen one of my best two views of Jupiter
through this scope. Certainly worth the $150 I paid for the primary!
Other hardware includes Novak heavy-duty mounts and trunnion rings, a JMI NGF-3
focuser, Telrad®, Parks 8x50 finder and some rings I got from Rex Allen (Rex's Astro
Stuff - 501.331.3773). I was very pleased to have achieved smooth motions in both
axes, due no doubt to chance more than any skill on my part.
This photo is about 3 years old, so you don't see the Lumicon NGC Sky Vector I've
installed. Also, it's been repainted, changing all the blue parts to black. Although
the scope won ”Best Telescope and Mount” at the 1992
Deep South
Regional Stargaze, I suspect this was strongly due to a lack of competition from
more skilled builders...
4 inch; Tele Vue
Genesis (commercial)
I had long heard of the Genesis' reputation for excellence. So, when I came across
an offer to sell a used one for less than a thousand dollars, I couldn't resist. This
one is an early model with a removable dew shield, rather than the style that slides
back onto the optical tube. Optically, it's a 4 inch f5.0 double achromat. I
say ”double achromat”, since although it's apochromatic in performance,
physically there are two achromat elements: one at each end of the tube.
It's mounted on an older Celestron
(Vixen) standard Polaris equatorial mount, which is more than adequate for visual work
with this size scope. I've replaced the usual adjustable tripod legs with 5' solid red oak,
non-adjustable legs for more stability. It's driven by a single axis drive with a dual
speed controller. Once again, this is fine for visual work and a few simple photos
could probably be coaxed from it. However, for real astrophotography, something much
more accurate would be needed.
The previous owner attached a couple of metal plates to the clamp ring, so I've been
able to mount both a 6x30 finder and a Telrad® to these plates, in addition to
using them as a mounting point.
In comparison to other scopes, I've not really done a serious direct comparison.
However, I was unable to tell any great difference between this scope and an Astro-
Physics Traveller on the same object at the same time. Any differences I saw were
probably ”local” in nature, meaning that they could be attributed to seeing,
indiviual differences in these particular scopes or my vision. All in all, it's a
great telescope, really nice as a small deep sky instrument. The combination of a
Genesis and a 9mm Nagler or 27mm Panoptic is impressive, to say the least.
6 inch Dobsonian, re-homebuilt
Although this isn't my scope, I've included it here since I recently (re)built it
for my wife's uncle. I bought the OTA (optical tube assembly) and built the mount,
although I pretty much rebuilt the OTA as well. The full-thickness f8.06
primary mirror seems to be good, but it's of unknown pedigree since I don't know
who made it. The primary mount appears to be either one of the older Jaegers or
University Optics mounts. The secondary mount and spider were of a type I'd not
encountered before. A Meade focuser and Telrad® finish it off.
After waxing the laminate used for the altitude bearing, this mount is probably
one of the easiest-moving Dobsonian mounts I've seen. However, that's not too
uncommon with small (read: light-weight) Dobsonians. There's one additional part
of the telescope that is absent from the photo: a handle on top of the cradle box
for carrying the OTA. I must have been inattentive when cutting the background off
of the original photo image (shot in my living room), as I also cut off the handle!
Apparently, it was one of those late-might photo editing sessions...
