Post by Chicago Astronomer - Astro Joe on May 22, 2012 23:48:52 GMT -6
Some Daylight tests with Solar Filter and motor drives
22 May 2012
22 May 2012
After the Partial Solar Eclipse of the 20th of May, I left the equipment cases and bags open to dissipate the rain drops that fell on my equipment for a spell. A day later, I went back Tuesday to close everything up...but it was such a nice day that I took advantage to tweak and test.
My tracking motors have been mis-behaving since last fall and during the Eclipse, the gear cover fell off on one of them...spilling a plastic gear to the pavement. It was C.A. Tom that saw this...lest I lost it forever. Placing it in my pocket, I took advantage of the free time this afternoon and worked on the motors a bit. With some tweaking, they both seem to work now and I used the Sun to test the tracking...which they did...but not 100%...but better than before.
On the subject of Solar....
C.A. Rich is using a "Solar Finder" disk on his scope...and I had one banging about in my accessory drawer someplace...and thought I would try it out....
Usually, one finds the Sun in a filtered scope by it's own shadow...and with good results. Another way is to use a device like the little nipple-like protrusion on a disk to slew to the smallest shadow...
I wasn't too keen on it. What it displayed and what was actual were two different angles and I did better by OTA shadow and trained eye. In cases where a screen or shade blocks the Sun...it can be of great value...but I need to play with this some more.
And...since the scope was out, I snagged some quick solar shots...
These last three pics were taken with a pocket Polaroid 8 MP camera...with half decent results. But I will try my cell phone camera next time, which delivered the best solar pics so far.
Now, visually...I was getting some great details on the sunspot structure, faculae and granulation...but photographically...things do not come out as sharp...losing a lot of detail. It's always tough focusing on the solar surface, but even on the LCD screen or Viewfinder..I was having a hell of a time getting true focus. And even when I did, the resulting pics were disappointing. When I was shopping for the full aperture filter, I came across filters that were either for visual or photographic needs. I'm assuming the wavelengths are slightly different for each purpose. Perhaps after the transit, we can all get filters for cheap...and I'll get an appropriate filter for imaging the sun.
Some more testing and tweaking in the next week...
