This is a new post to share my project to build an 8.25" folded refractor using a doublet of f/27 and two optical flats.
I purchased these optical components from the legendary Edward Byers a few months before his passing, a great loss to us all.
Ed had a pair of these 8.25" doublets and had planned to construct a folded binocular scope for solar observations. He realized he did not have time to complete this dream project and sold the optics. I knew the binocular project was far beyond my capabilities and so I obtained the optics for a single telescope. Ed assured me the optical components are top notch. He expected results comparable to a Clave lens...all I can say is holy moly yer kiddin me right? The doublet was figured by a master optician and mounted in a cell by the Byers Company.
All the initial observations I have had with the folded refractor I have cobbled are like WOW. Cassini...there. Mars surface detail...obvious. Jupiter Red Spot...well yeah. The Moon...is that Niels golf ball. Really exagerating on the last bit, haha.
Ed provided a layout for this folded refractor which I used as a model.
My OTA is built of baltic birch with old 6" primary cell mounts to hold the two flats, 6" for mirror 1 and 5" for mirror two.
A 2.5" Feathertouch completes the optical train.
Brandon eyepieces all the way and a Vernonscope binoviewer to boot.
Lets see $$$$$ but well worth it. Accumulated over decades (hope I'm not too old to see by the time I get this completed!!!)
The scope is not fully assembled since this is a trial and error project.
When I have looked through the scope...a most difficult operation as it is not yet properly balanced (will document all the counterweight issues at some point) and the drive is not connected, anyway...
The view through the focuser can be confusing. I made a baffle but I still see reflections from the second optical flat.
I have been reviewing Texereau and the Book cover has a diagram of a Cassegrain scope. I have an 8" Cave Cassergain and my scope conforms to the Texereau diagram down to the long draw tube that limits the light exposure to the eyepiece.
Light bulbs are flashing...although not original...could I install a tube of pvc or somesuch inside the OTA to serve not as a drawtube but as a baffle for the focus end of the folded refractor? I'm thinking, Why not?
Edited by VVObserve, 28 November 2020 - 05:39 PM.