clear sky chart

Job 9:9

Job 9:9-10
9 He is the Maker of the Bear and Orion,
the Pleiades and the constellations of the south.
10 He performs wonders that cannot be fathomed,
miracles that cannot be counted.

Saturday, April 28, 2012

Messier 5

Since the moon is now out, I sort of gave up on NGC4565 for now and instead concentrated on some globular clusters.  The first set of images I did not have the telescope polar aligned properly.  I was in a bit of a hurry, and I ended up with streaking stars.  Since I got that focusing mask, I've found alignment is more critical, as poor focusing hides other imperfections.

Also, I learned something new about the stacker, and the settings I've been using.  My images have been coming out on the bright side, and it was very difficult getting rid of the noise.  I was limited by noise as to how much I could stretch the histogram to bring out faint detail.  The trick is to save the image without applying any settings that were made in the stacker...or do not modify the brightness curve.  My images show the spike to the left of the histogram curve in the stacker.

The images come out really dark when brought up in photoshop.  A very aggressive stretch will bring up the detail without increasing the noise as much as if the brightness was increased in the stacker.  When I was able to stretch the histogram to the point where the noise started to creep in, I was able to get about 10 times as many stars as before, as you can see in this image...

I also removed what noise remained, which was easy being there was so much less noise using Noel Carboni's Astronomy Tools v1.6.  A little bit of unsharp masking brought out a few more stars, then increased the star color saturation using the above toolset brought out a little more color in the stars.


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