Staring at the Sun, 4
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6/19/2010. Lessons of the day:
Canon 50D (unmodified).
Lunt LS60T Ha. Double-stacked. 1/8s, ISO 400.
Same image, red
Bayer plane extracted in Maxim DL5, limb and disk detail
Late in the afternoon, I tried a TeleVue 20mm Plossl in the B600 and found a much brighter (and smaller) Sun waiting in there. Maybe this is the eyepiece to adopt for a quick look. The 7mm Nagler shows much more detail, but owing to the dimness of the comparatively large image, it requires much more concentration. A robust subset of all available structure is visible at a glance in the 20mm. When using the 20mm, I see why people prefer the 12mm blocking filter. With a driven telescope, it doesn't feel claustrophobic because the difference between black sky behind the Sun and black sky behind the field stop / small blocking filter is not visible. Nonetheless, the field around the small, bright, detailed solar image is small. If you don't aim well, or if you let an undriven telescope drift for more than a few seconds, the Sun bumps into the black edge of the field (image diameter 4.8mm) will begin to slide behind the edge of the field of view (field stop / filter diameter 6mm) in less than 20 seconds.
Late tip found in a Lunt forum post by Eric Roel who does lovely solar work from his observatory in Mexico: histogram equalization is part of image preparation. A quick trial shows this to be a promising, timesaving step.
Nostalgia warning! So, who remembers "The Mr. Bill Show" out of Asheville, NC, on WLOS-TV 13 that used to run every morning, rain or shine, hell or high water, in the middle and late 60's? Mr. Bill (Norwood) was the meteorologist for WLOS-TV (I learned this while Googling him) who had 2-1/2 hours to fill every weekday morning. He ran cartoons, Three Stooges shorts, kids' news (school closings, simplified news stories), just about anything, including what I remember best: science segments comprised of killer footage from this or that project. I vividly remember film clips from the Lyot coronagraph in Boulder, CO (?), showing time lapse images of solar prominences in hydrogen-alpha light. Maybe he ran that film only two or three times in his entire career (or, hell, maybe I remember them from the old "Discover" show that also ran before school in that era), but I so remember those clips. And I remember going to K-Mart's photo counter to inquire about a hydrogen-alpha filter so I could see such things for myself. I figured, hey, it would cost $50, and I would have to save up for one, but it would be worth it. It took 40+ years, and a more substantial cash outlay, but really, this is my flying car. What's become of Bill Norwood?
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