Hi! If you should name two components as THE most important two for making a stable EQ mount with high load capasity(*), what would it be and why? Best Wishes,...
There's more then 2 but I'd start with large diameter RA and DEC shafts with short overhangs and large diameter pre-loaded bearings. Tony ... There's more then...
Richard is absolutely correct on this one ... The Dall-Kirkham achieves perfect on axis images, however it is at the expense of greater coma at the edge of...
... And, if you're real picky, I found this site with info about field correctors for RCs the other day. More qualitive than quantitive, though, in that it...
Hi: If I have the Zernike Terms of a mirror, is there any easy formula to find the best fit conic constant from these Zernike Terms? For example: r of mirror=...
Hi all, I recently hear that Robert Lurie had made the first Lurie Houghton telescope in 1979(sorry I forgot the information source), In this situation we can...
Ukyo Chen
ukyochen888@...
Nov 3, 2005 4:01 pm
7344
Dear, Do you have issue Nov 1979 of S&T magazine? Or just the article 'Making an Aplanatic 4-inch Telescope' inside the issue? I only can find free preview ...
Ukyo Chen
ukyochen888@...
Nov 3, 2005 5:25 pm
7345
Ukyo Chen, If you can't find the article any where else, I have it and can scan it for you if that will help... Coyoté ... 'Making an ... preview...
I know that there is an earlier version of the Houghton described in the Mak Club circulars around 1971. It has three corrector lenses and a mirror, all ...
And... what many fail to realize is that figuring an R-C primary is no more difficult than an ordinary parabola; just divide all of your tester readings by...
Earlier this year, around March, Bob May extended an offer to lend his focaultcam out for mirror testing. I became interested in mirror making after buying a...
Hi Richard, Long time no banter ... I think the a war got in the way last time we were on about Richey-Chretein systems and their Classical-Cassegrain, and...
Hello Ukyo Chen, The Houghtons were originally introduced in 1944 and all comprise all spherical optics...ie, correctors 2-3 and primary mirror. The...
is this solution permit to observe from the side or whiout any secondary what it call and of axis or scout scope or some deformations still appen when you...
So, would it be possible to replace the two or three lens corrector assembly with a single aspheric plate similar to a schmidt corrector? I guess it would be...
Yes, a Schmidt corrector can be substituted... however for best results the primary mirror would need to be figured to an oblate-spheroid of figuring exactly...
I almost forgot to mention that the corrector would would be figured with a relative power of 2, or twice that of a standard Schmidt camera of equal focus... ...
You're welcome! I'll note that if anybody else wants to borrow the camera, I have it available for the cost of shipping it in the US. I'm not shipping one of...
Long focal length spherical mirrors can be used as Herschellian type telescopes if you want to have an unobstructed telescope. Bob May bobmay at nethere.com ...
I found, i believe to be the cause of the slight lines in the polish. There was a small piece of pitch, around 3 or 4 mm long on the edge of one facet, it's in...
The depression in the one facet won't cause any problems with the polishing. In fact, all of the facets could have that same type of depression and the polish...
So i've polished for 40 min right? The mirror still has those lines in a ring form around the center that seems not to be polishing. But I got the Ronchi...
... It sounds like you have a sphere within a sphere and based on your discription it sounds like the center of the mirror is deeper with a shorter focal...
... a ... So i know for the future, what might have caused this? Held up to the light the mirror looks fine but i'm sure that means very little. ... lol, i...
Hi all, Regarding to my 5" Lurie-Houghton telescope project, lenses part finished already. Now 2 126mm correctors with multi-coating, 1 126 mirror with ...
Ukyo Chen
ukyochen888@...
Nov 8, 2005 1:34 pm
7368
I think the subject title says it all. I would like to know the best/easiest way to remove the wax from a sonotube to prep it for the polyurethane coat. ...
... Hi Ukyo, Congratulations! You already have come far with your LHN project. Just wish you would have done the grinding and polishing work by yourself. Then...
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