Tutorial: Processing Prominence Images (Cai-Uso)

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Merlin66
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Tutorial: Processing Prominence Images (Cai-Uso)

Post by Merlin66 » Wed Apr 18, 2012 12:56 pm

Tutorial: Processing Prominence Images

First acquire a prominence sum image out of e.g. AviStack. Make sure it has a bitdepth of 16bit (it normally does if the avi was recorded with a DMK camera).

Then use the first unsharp mask in Photoshop. The radius value depends on the seeing you had while taking the avi. The better the seeing the lower the value. I use values between 0.7 and 1.2 pixel.



Afterwards you have to blur the image a little with gaussian blur. Here I always use 0.3 pixel.



Then we sharpen again, often with a lower value of radius than the first time.



To go on processing the bit depth (in PS 7) has to be set to 8 bit. You do not need to do this with Photoshop CS though.



Now we will darken the surface. Therefor we have to set a round mask between surface and chromospere. The diameter of my mask (with a focal lenght of 1800mm and a DMK 31) is something inbetween 3600 and 3650 pixel, depending on the distance Earth-Sun.



Then we will invert the mask to set levels to the prominence side.



At last we set the levels for a nice prominence image. Feel free to experiment here.



I hope my tutorial was not to difficult to understand.
And now you should try your own prominences!


You can also see this tutorial on my Homepage:

www.cuwohler.de --> Artikel --> last article
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.yahoo.com/neo/groups/ast ... scopy/info
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

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