"could you make the 48 inch work?" Not sure how much fold I could put in it but I have a 48 inch F/10 Chief design, diffraction limited over the spectrum. Of...
I've come to suspect that part of the popularity of the open truss telescope design for large apertures is driven by the perception that sources of large...
I posted a design for a 48 inch f/10 Herschelian not that I expect anyone to build one but just to show that old Herschel could have mad e really spectacular...
Ed I have this really BIG Hershelian telescope! I can get a "Wide Load" permit to pull it down the highway but it won't clear the overpass! The FAA is...
I have posted a file called "16 inch Mangin-Chief" that uses a mangin secondary to get rid of coma and lateral color. The primary is hyperbolic and the...
Art, The Chief is a great planetary scope but also a good all around scope. It's not as low a power as some of the Dobs are but the eyepiece location can be as...
very cool ED/ as you know i have a 16 f 10 blank on order from newport .so some kind of 16 offaxis will be made.looks like at f 10 you can have the eyepiece...
I notice the secondary has long radii, with relatively small diameter. I have just done a long radius mirror of 6" aperture with a radius of 300"~ I think...
HI MARK sounds like you are the guy to make me a Chief mangan corrector .kevin . ... From: mdhopt53 <maralees@...> Subject: [spiderless] Re: Coma...
Hi Tony! I just now spotted your request for info. Sorry for the delay. The photos in the picture section were taken of a tube purchased locally at a building...
Mark, Obtaining a smooth surface on these would be no different than doing a flat plus you would have a few fringes of tolerance that you don't normally have...
Playing around with Zemax I found that you can get about the same results without using a mangin using a very long radius hyperbolic secondary. I'll post the...
One more thing I discovered about this design (sorry for all these short posts). The secondary can be flat or curved over a wide range. However if I make the...
They're a whole different ballgame when it comes to making the thing. I found that the pitch layer on these long radii pieces have to be essentially the same...
Caught!! I was so busy trying to be cute I wrote Hershelian when I was thinking of the Shupman. How could anyone confuse the two! Art ... It's not as low a...
The dates for NEAF 2010 have been set for Apr 17th-18th. Typically there is a seperate imaging forum the day prior to the Saturday and Sunday exhibits. Save...
Maybe your mean doing flats on a large planetary polishing machine then yes you're right, a flat is fairly straight forward. Doing a flat or one of these long...
Never said that, I never used the planetary rig. I made flats in batches of 50-100 at a time, with generally 6 spindles going. I averaged one in 15 minutes to...
Please don't get me wrong, I'm not saying they can't be done easily, just that it took me a week to figure out the variables to do a 6" F/25 concave mirror!...
Looks really nice! It'd be great if we could hear about a comparison between the formentioned Newt form, and the Chief- could you persuade him? Mark...
I didn't hear him talk about a comparison before and after, he was pretty excited about the design though. He kept telling my old boss "you gotta build one of...
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