To control dew on the C14, get a custom Insulated Dewshield from Richard
Just at ricvic@... . Also, a dew zapper helps, otherwise.
Richard can make a dewshield to fit your exact needs (mount etc.). The
shield covers the entire tube and extends out front. They are the only ones
that work. Kendricks doesn't cut it on a 14" piece of glass, and if it did,
it would take so much current and cause so much thermal convection so as to
drain even the largest battery and ruin your seeing.
Yes, A G-11 is stretched in supporting a C14 but it is a better choice than
the CI-700 mount (I have used both). There will be some vibration and
shake, but it is acceptable for visual use. Not so for imaging, where only
the best mounts prove adequate. However the gain in performance over a C-11
is well worth a little extra vibration.
The place to buy the C14 from is ASTRONOMICS. You wanna spend more? Buy
from someone else. No one, not even C7 guarantees a superior scope. All C7
does is check for obvioous flaws and obvious substandard quality (rare in a
C14). You can do that yourself for free. A good dealer will allow
return/exchange within about 30 days or so if such a serious problem is
found. If you cannot detect an obvious mechanical or optical flaw in a
telescope, then maybe you shouldn't be buying a $4,000 SCT! There is also a
1-year warrenty. Also, if you cannot detect such problems yourself, then
why worry or spend the extra money? Whether you have a problem or not, you
won't know the difference! Of course, if you are really insecure or just
like buying very expensive tools which you know nothing about and / or
aren't sure if you really want one but sorta think you might like to try one
and then find out it was really a mistake after all and sell it for a loss
to someone else, then by all means spend hundreds of extra dollars on it and
have a more knowledgable person profit from your ignorance! I can only tell
you that C7 and others like them take what they get from the factory, there
is no hand-picking. It only goes back if its a real lemon, and I would hope
you can tell a good scope from a real lemon yourself if you got the bread to
spend and want something like a 14" SCT!
In getting a 14" OTA, look for cosmetic blems (1). I had a few (scuff?)
marks on my tube, but I bought the scope to look through, not at, and they
are not that noticable. In the dark, their not seen at all. (2) Look at
the window and interior. It should be clean. (3). The focus should be
smooth and even, without a lot of slop and play. Image shift should be
minor, even at higher power. (4) [after collimation] Looking at a bright
star overhead in the center of the field at very high power under good
seeing, the out of focus image should be: (a): symetrical on both sides of
focus, (b) identical in the distribution of energy in the diffraction rings
on both sides of focus. There should be a brighter inner ring next to the
shadow of the secondary, a couple of thin middle rings, and then a brighter
outer ring similar in thickness and intensity to the inner ring. And yes,
if you rack out further, you will see a tiny white "dot" of light in the
middle of the secondary shadow. That's normal too. It's a function of the
wave nature (addition and cancellation of phase energies) of light. Don't
worry about it. The diffraction rings should be smoothly and evenly lit
(under good seeing). (5) You will have some astigmatism and coma at low
powers unless you use the corrector/flattener (buy with scope). This is
really an f/2 telescope, don't forget, and an ecconomical one for what you
are getting.
If you want a perfect scope, you can spend $12,000 for an 11-inch
Richey-Chretien from OGS.
Relax and enjoy your immensely powerful scope you bought for only 4G (a mere
pittance in today's economy).
If there's anything here that confused you, don't worry. There are many
good books on telescope design and theory. The best are Amatuer Astronomers
Handbook, Telescope Optics by Rutten and van Venrooij, and Suiters Star
Testing. Support your country and help your economy: BUY BOOKS. READ
BOOKS. You will love learning !!
Hope this helps out.
Wayne E. Gondella
AFA Engineering Company
Pittsburgh, Pennsylvania
