THE SUN - AR 1890

November 11th, 2013

Eastern limb of the sun with sunspot 1890. To give a sense of scale, one could fit many Earths in the darker, central region of the sunspot.

Nice contrast between the two regions. I wonder if you can somehow calibrate this to actual Kelvins and measure temperature.

One shot with modded 7D through a 200mm / 2.1m catadioptric.

Great shot. What are the modifications to the 7d?

Excellent image. I'm looking to get some filtration for my TAK Sky 90 and would like to get the best solar filter I can get without breaking the bank. I'd love to have H-alpha but I can't spend $4k right now on a Coranado. I'm looking forward to the total eclipse here in 2017 and would like to be set up before then, I've been wanting to get into solar for a while. Do you have any suggestions?

Here's a link to some temperature range in the umbra and penumbra areas of the spot. No way to tell how yours compares but it give an idea of what the differences could be.
http://hyperphysics.ph​y-astr.gsu.edu/hbase/sol​ar/sunspot.html

neimad19 wrote in post #16455754
Great shot. What are the modifications to the 7d?

I've had a friend remove the IR filter and replace it with an Astrodon Ha pass. It broadened the range in the reds and made it more nebula-friendly (scary pictures here: https://plus.google.co​m …2158324/posts/2​84AqKeez9i ). White balance is now warped and autofocus has shifted (fixed by shooting raw and micro-adjustment)

Nighthound the sort of solar imagery I do is really cheap: a USD 20.- A4 sheet of Baader:

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