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An M-Class Flare
8/7/2010: I
got a good look at the Sun in the middle of the afternoon just
as clouds began to move in from the south. Did a double take. A
very complex, very large, very bright flare was wrapped around
an intricate region of chromospheric detail (AR 11093). And then
a cloud covered the Sun. It was a small cloud but it was moving
excruciatingly slowly. I checked the Sun's x-ray flux using the
link above and was not at all surprised to find an M-class flare
in progress and near peak intensity. Thirty-five long minutes later,
there was still plenty to see:
Lunt LS60HaDS50, Canon
50D, iso 400. Two barlows on prime-focus adapter. Red Bayer
plane isolated in Maxim; 50 x 0.25s stacked in Registax;
Focus Magic for deconvolution. Levels adjusted and different
treatments of limb detail in Photoshop. Click the image
for a closer view. There's a lot of detail in there.
More photos to come but there's a LOT of data to
work with today. I think these images can be worked better than
I've managed so far. Stay tuned.
Blue arrow indicates when the photos
on this page were made.
Best 8 frames
selected, aligned on multiple targets in Registax,
wavelets applied, Focus Magic deconvolution, cropped,
histogram equalized, unsharp masked and colorized (and not).
Once again I am astonished at how tough it is to
keep all the details sharp without letting the images get all harsh
and noisy. Clouds. I could use a good spell of clouds while I figure
this out. Another thing that routinely astonishes me: this is not
the 2.4-inch department store refractor of my youth.
D'oh! It's dope-slap time.
What do you do whenever the dynamic range of the image exceeds
that which can be neatly, pleasantly displayed? Dynamic masking,
people. I've been doing this for years for all sorts of subjects,
so today it takes me 9 hours to remember to give it a try?
Here it's been applied very late in the workflow, to the
8-bit output image. Works OK. It'll work better soon. (Quick
guide to dynamic masking in Photoshop: copy the entire
image into a new layer on top of the original; invert the
new layer to a negative; change blending mode to soft light;
work the curves in the negative layer to lighten or darken
detail; flatten, continue as needed.)
Here are time lapse clips from the Solar Dynamics
Observatory in orbit. The video repeats the flare as seen at several
far-ultraviolet wavelengths. The images above were made at the
deep red wavelength of hydrogen-alpha light (6563A) while the SDO
recorded the event at wavelengths from about 100A to 400A.
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