A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Mark Coady
Date: 2016 Mar 21, 18:28 -0700
Sat morning I was in the courtyard of the mystic planetarium with a Cassens & Plath recently obtained in as new condition. While I had not yet put it through all the paces of super tunup, It appeared to be in decent tune. index correction looks like .2 off scale, and side error almost nonexisitant. Index mirror looks good on a visual of the rack. I will be testing it with my brass cylinders shortly.
With nothing terribly distant, I decided to use the sun check technique based on SD for a quick index check.
I flipped about the same shades of filters I use on my astra, set it to 0, and pointed it at the morning sun, expecting to see two suns as I moved the mic back and forth. (note: was using my celestaire 7x scope off my astra)
Well I had those two and several more reflected images. at regular intervals. Too many Suns! This is not something I have encountered before.
On a quick inspection the only thing i found amiss was the index filter mount screw was softly set enough so a bump might have knocked the filter mount a little off their normal position. (rotated slightly on the frame).
Obviosly index mirror to filter angle is normally not an issue, one is fixed, one rotates.
So I have to go play eliminate the variables and try to replicate it when the sun comes out.
My assumption is I am picking up multiple reflections off something. Just not sure what yet.
Has anyone experienced this? If so have you found that simple obvious explanation I have not found yet.
I figured I can do the moon without filters, and try dark paper slid in and out with the sun to try to find what and where blocks the extra images.
I wondered if it was environmental (surrounding windows, atmospheric, etc.) as I don't recall it before. When i first looked at it on the dock when I bought it I had done the sun check and remember noticing it doens't have the off color filters like the astra to make the direct and reflected images different colors. I know I saw only two suns.......
I also don't know if I had tried the prism scope on a check after. It came with a 4x scope, and I swapped the 7x on dreaming of lunars.
Just curious if already been solved before?