HI ED doing some thinking about height of the eyepiece on the 20 in f 8 CHief it is 85 inches// wow a F8 that is shorter than my 20 F5.25 it is 91 inches...
Kevin,  sounds great, I have a 20" F5, feet of the ground would be great. What part of the country are you in? Would like to me you and your scope one...
I am purging my old and odd collection of EP's and upgrading to the quality I didn't appreciate when I first started this pastime. I'll retain my better 1.25"...
Art, I don't know what the real field size is but roughly 100deg/164 power is .6 degrees. I design to cover .5 degrees so worse case you will see a slight...
I posted a number of pictures on how I made my equatorial platform. Using my table saw and a sanding disk I made very smooth and accurate bearings out of hard...
Ed if there is a simple way to explain the formula by which you arrived at "100deg/164 power is .6 degree" field of view, I'd enjoy your explaining it. The...
Art, The second question is easy, that was a Zemax calculation. I was assuming you were getting the 13 mm ethos which would be 164 power. For any eyepiece the...
For a 12.5" f/8 telescope (focal length = 2540mm), a 13mm eyepiece yields 195x. Ed--How did you get 164x? Is the effective focal length changed? Art--As far...
Art, Somehow when I did these calculations I was thinking your mirror was f/7 instead of f/8, my mistake. I attached the prescription of your scope in word...
Hi Kev,  Thanks for the invite, what part of PA? I am outside of Bethlehem? Would love to see what a Chief can do.... I have a 20" F5 that should be...
Thanks Ed! The timing is perfect. Yesterday my new Bosch dual miter saw arrived and I used it to trim the wood framing to length and make triangular gussets...
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the spiderless group. File : /Chef...
spiderless@yahoogroup...
Jun 16, 2009 3:29 pm
451
I put a new Chief design in the files called Chief refractor. It is very much like a Yolo except the secondary is flat and smaller. It is diffraction limited...
Hi, Folks. Having built an 8" folded achromat about 10 years ago, may I suggest that the fold flat be tilted so that the beam resembles the letter "N," rather...
Roger, Niether are as good with stray light as the "standard" Chief. I think the Yolo form is a little better than the "N" form because like the Yolo you can...
Hi, Ed. But if you increase the primary tilt a little so that there's some space between the edge of the flat and the incoming beam, then complete baffling...
Hi, Ed et Al. I uploaded a folder with a suggested tilt arrangement for an 8" f/15 Chief that would be like a folded refractor, in the "N" arrangement. It's...
Roger, You can do a "N" but you have to put a lot more tilt in the primary to make room for the baffle. Extra tilt reduces the Strehl and increases the focal...
Hi, Ed. In principle it sounds bad, but at f/15 there's a lot of optical wiggle room, I think. If you examine the folder I put up yesterday (8" f/15 Folded...
Good luck! Hope it turns out well! Roger ... From: Ed Jones<mailto:opticsed@...> To: spiderless@yahoogroups.com<mailto:spiderless@yahoogroups.com> Sent:...
Hi ROGER the nice thing on the CHief is you can change  the eyepiece placement and the optics stay the same // cool little corrector can do a lot// / I/ve...
Hi All, Just a few thoughts regarding stray light suppression. Having designed and built various TCTs over the years, my personal experience is, that...
Guntram, The Chief in the "Dob" form has both minimum tilt and excellent baffeling. It is only when you want to do a longer fold does the issue of baffeling...
Ed, yes, the "Dob" form is excellent when it comes to baffling and tilt angle. All right here. You guessed it, it was a Schief, an anastigmatic one, to be...
Hey guys, Longtime lurker here!! But I have a couple of questions about the "refractor". 1) are the correctors "off the shelf"? 2) in the folder labeled "8in...
Hi, Chuck. I didn't select the lenses for the corrector with an eye to what's available commercially ("off the shelf"). The design was just meant to suggest a...
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