5.3.19

5.3.19 Solar + binoviewers.

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Tuesday: 49/45F Very cloudy with westerly gales reducing. Had hardly more than a  few seconds of sunshine all morning as I tried to test the binoviewers on the sun.

First I took some pictures through the binoviewers looking "backwards" from the telescope side towards the eyepieces. Once downloaded I had triple images with much weaker images either side of a solid central image. But, the views looked fine naked eye. I needed to use my TZ7 zoom to fill the field of view.The images were all doubled again. So it seems testing the binoviewers backwards with a camera doesn't work. The original binoviewers showed duplication when viewed backwards, naked eye. The new ones are fine viewed backwards, naked eye.

Onto the 7" telescope with the binoviewers: Okay up to 113x terrestrially @ 600 yards distant trees used "straight through." A bit of false colour visible around the silhouetted twigs but nicely sharp. No eye strain nor any other symptoms detected.

Unable to use the binoviewers on the 7" with the Lacerta prism in place. I'd have to shorten the main tube. Best to wait for a clear day to be certain of the exact focal point required by the big solar prism.

Back to the 6" and H-a. Fine with 32, 26 and 20mm eyepieces used straight through. [For 41, 50 & 65x] A pair of 15mm EPs would probably fill the field of view with the sun's disk. I'll have to find another secondhand example of the 15mm 4000s. The surface textures was much more even than using one eye. The binocular view also suppressed my eye floaters. [Debris floating in the liquid which fills the eyeballs.]

Unable to use the same set-up with a 1.25" star diagonal. Not enough back focus on the end of the PST Swiss AOK Etalon fittings to 2" then T2. What I need is a shorter, female PST etalon to T2 male thread adapter. The 2" fittings have a finite depth of socket to suit the spigots on standard 2" fittings and adapters. 

So then I tried the TS GPCs. 1.6x and 2.6x. The 2.6x was far to much power even with the 32mm. The lower power GPC worked with the 32mm EPs but I didn't have remotely enough sun to pursue the potential.

After that there was no more sunshine at all and it suddenly turned to a noisy hail shower and then there was heavy rain just as briefly. After which it dried up and brief spells of weak sunshine kept teasing me back to the observatory.  


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