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10" refractor without mount?
I found this add and was wondering if anyone has any input on this scope and is it worth me purchasing it?
10" f/10 refractor OTA sleeper. Government issue by Thompson Optical in California. Fully baffled rolled fiberglass tube. Dew shield, rack & pinion focuser w/ 2 inch and 1-1/4 adapter. $4,000
I believe the scope is from the early 70's. It was made by thompson in
california. When the gov shuts down programs they auction off
equipment, instruments, etc. About 15 years ago a friend of my was
head optician at kitt peak and put an offer in a sealed bid on 3-10''
refrac. one was sold to a planetarium ,my friend and I each took one.
The baffle system is really cool. It has 6 baffles with 4 aluminum
tubes welded to the baffles. It looks like a miniature mt. wilson
structure. I have the scope on a german equatorial with a huge worm
drive. The whole thing looks very antique-y. The 3" brass jaegers
refractor is used to balance the system. This is an optical tube
assembly only. I've hardly used the scope because of size, and I've
spent a lot of time on prep.
3 Answers
- GeoffGLv 79 years agoFavorite Answer
Start by doing the math: 10" x f/10 = focal length of 100" = 8' 4"! As a teenager, I got to regularly use a refractor with a 100" focal length, and it was only 6.5" aperture. Still it required a massive equatorial mount and a domed observatory. The problem with this scope is that though it's very inexpensive for its size, the mount and dome to house it will cost you three or four times what the OTA costs. Only for the very rich! As an aside, any achromatic refractor should be at least f/15; and f/10 will have horrendous chromatic aberration.
I've never heard of Thompson Optical. The only company making large achromatic refractors nowadays is D&G (see below).
Source(s): http://www.dgoptical.com/refractor.htm - Anonymous9 years ago
Definitely! It sounds like a great telescope, but it is just an OTA (Optical Tube Assembly). Therefore, it might help to get a tripod (From Orion. They have the best, yet cheapest, mounts. By the way, I don't work for them. Google them!)
EDL
- Anonymous9 years ago
If you've got the money to buy it and to mount it. And a place
to put it. I say.....GO FOR IT!
<EDIT> Of course, GeoffG knows infinitely more about
telescopes than I will ever hope to know.
