Another good thing about having a Questar - never a need to climb a ladder!
Black Hole Gang Reminiscence
Posted 13 October 2018 - 10:33 AM
Jeff, I know just what you need!
- steve t, jcruse64 and AstroKerr like this
Posted 13 October 2018 - 01:12 PM
Tim, that would be nice. I still dream about building the 16" f/50 Cass. It would have been a honey. For others to read about: http://www.alpo-astr...sh/Cass_Equ.pdf
The 12,5" f/30, third generation, was great and with the smaller secondary images were like Newtonian and high contrast. Too bad the primary was messed up at coating.
Posted 13 October 2018 - 01:25 PM
I've got another Springfield mount head that I bought off Ebay several years ago: https://www.cloudyni...ingfield tim53
I'm currently seriously considering putting the 16" Mak Cass on it when I finish that project, though I probably can't start on it for another couple years: https://www.cloudyni...?hl= mak tim53
Either way, probably permanently mounted, once I get an observatory together at our Cosmic Acres property: https://www.cloudyni...0-cosmic-acres/
A couple nice things about a Springfield Cassegrain:
*The image is direct (though it takes 4 mirrors to do it).
*One can remove the tertiary mirror and put a focuser in the standard Cass focus position for photography.
*It would be possible to piggyback something like a 6" refractor on the Cass tube with a secondary to direct the light cone through the Cass tube to the fixed eyepiece, so that you could view through the refractor while imaging through the Cass.
Posted 13 October 2018 - 02:11 PM
Yo Tim, that looks like Mars and you discovered life in the Red Planet!!!!! Joshua Tree?
I remember observing with one of your Springfield Casses at RTMC back in 1994. Nice stuff and easy to use, wooden tube as I remember. One of my former friends made one but his was a refractor and had so many collimation adjustments it took Don and I two days just to get it adjusted. That scope was the closest thing to a Rube Goldberg gadget I had ever observed with.
Edited by Jeff B1, 13 October 2018 - 03:12 PM.
Posted 13 October 2018 - 02:56 PM
Collimating sure was a problem with that one. But that was before lasers and accurate machining of parts. Next time...
Posted 14 October 2018 - 07:48 AM
Here's a scope you may remember, Tim, he started grinding the 6" f/8 mirror in his teen years (1950's) and finished figuring it in the 1980's. I coded up a PC program to help calculate the zones and we determined it was so close to perfect he hesitated getting it coated When he would take it to the WSP lines would form at it for hours. It was pure in the Foucault views.
- tim53, steve t, rcwolpert and 1 other like this
Posted 14 October 2018 - 08:25 AM
Yes, I remember that scope! He let me use it when I came out for the flash observations in June of 2000. It had remarkable optics!