An unexpected sky

06/24/2024. The astronomer's forecast for today did not look promising, but the morning (and afternoon, and evening...) were clear and blazing hot. Who am I to not use a clear sky when I have one?

I started with some close views, then tried a couple of 6-frame mosaics. Yes, a single layer of "postal plastic" with the Sun centered and defocused makes a good flat. As it turned out, one frame (the "5 o'clock" frame) contained arcade loops from a long-lasting M-flare that fired off just over the limb early this morning. I didn't see the flare or the loops while I was taking data and had no idea this show was available, but I have made the best of one of the mosaic frames that just happened to catch it. I'll try a bit harder after posting these notes 'cause I have ideas. (There are some wonderfully sharp images of this little boomer on the SolarChat forum.)

 

Six of the best. Best 98 of 500 times six.

Best 98 of 500 frames, arcade loops salvaged from a full-disk mosaic frame.

Best 500 of 10,000, ~1000x780 ROI.

The seeing was off, but the tracking was good, so I thought, why not let it roll? But it's really the only decently sharp image I have of active regions today. I spent tons of time processing others, and I thought the data looked pretty good. When it came time to post them, I realized that something was off. Maybe the focus was soft; maybe the seeing was worse than I thought; maybe I screwed up somewhere along the post-processing line. Tomorrow morning's seeing is forecast to be excellent. Rather than torture today's data on into the night, I may wait and try again then. I do still have ideas about those loops, though. If you don't see more of them down below, those thoughts didn't pan out.

OK, about the best I'm going to get is this, the result of a few hours of obsessive experimentation. I wouldn't swear it's an improvement over the stuff I did earlier. The more I look at it, the less I think it is. Today's lesson: check online resources before hitting the field, and take a swing around the limb of the Sun before closing up shop.

 

 

06/25/2024. Seeing today was forecast to be very good and it was (tomorrow's could be even better). When the air cooperates, you can see what really matters to sharp solar photos (everything!). The best improvements today came from carefully adjusting the parameters of the high-pass filter. I started with the AS!4 output, cleaned up the edges, gross gradients, tightened up the histogram to give ImPPG something to grab hold of while making sure there was at least a bit of head- and floor-room on the histogram, then made a L-R decon pass making very sure to stop well short of gross oversharpening: step away when the filaments around the spots are threads, not mooring ropes. Then I applied a high-pass filter, selecting only very fine details (~5 pixels or so). It didn't look like the high-pass filter would do much, but when I layered it over the ImPPG output (blending mode overlay), things looked like they're supposed to: velvet tones and details that really need to be seen at full rez (~3000x2300 after drizzling) rather than presented smaller to hide shortcomings. Bingo. More of this, please.

Beginning of a second encore for the group previously known as "3664."
Two frame mosaic (top/bottom), best 500 of 3,000 frames.

 

Closer. Best 300 of 5,000 frames.

 

It's so easy to overcook those noodles!

 

Two panels (left/right), best 300 of 3,000. This is the darkest variant of three, FWIW.

 

The two-panel mosaics worked out well; I did not try a 6-up full-disk today. The big deal for the day is the effective use of a high-pass layer and a reminder to not overcook the fine details when trying to find contrast. Subtle details do not need to be, and ought not be, vivid.

 

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