M97 - Owl Nebula...

[Edsport]

The skies finally cleared for me to grab a few subs of owl nebula. Half the subs was with the moon in the sky and half after the moon went below the horizon. I managed to get lots of subs this time but still it seems a bit grainy. 39 190 sec subs @ iso 1600 with no reducer.

[budguinn]

Very nice shot, Ed

[Dean Jacobsen]

That is a nice shot Ed. I still haven't managed to get one of that object yet.

What program do you use to process your images? When I downloaded your image into Photoshop I noticed that most of the left side of your image's histogram has been cut off by your processing. It looks like about 50% of your data has been cut out by the black point settings. Do you manually set the black point on your histogram or does the program do that automatically for you?

Dean Jacobsen
www.astrophoto.net
W6DBJ

[Edsport]

Thanks guys.

Dean, I use photoshop 6.0. I'm still learning about processing and i'm kinda lost as to how to process. Most of my images are like that if u downloaded them you would see. I set the black point myself. I click on the black eyedropper in levels and click on the pic then the data is clipped. I guess i am doing it wrong but i don't know any other way. I always clip the data. Any tips?

[Dean Jacobsen]

Hi Ed, my suggestion is to adjust your black point manually. You can do this with the "Levels" tool in Image/Adjustments/Levels.

With the exception of a couple of filters, for the most part, the "Levels" tool and the "Curves" tool are the only tools I use in Photoshop.

If you are processing an RGB image, you can set the black point by setting the channel box to RGB. You then can adjust the slider on the left [the black point slider] to your liking. I usually don't take the slider all the way over to where the histogram rises because I personally like the background a little lighter. Just make sure that you don't set the black point inside the histogram. If you do, then you are cutting out some of those photons that you worked so hard to collect. <g>

You can also work with each color channel separately.

I hope this helps a little.

Merry Christmas and a Happy New Year.

Dean Jacobsen
www.astrophoto.net
W6DBJ

[stargazer]

hi Ed,

this is a very nice image of a very difficult object, as it is so faint.
the remaining noise could easily be removed with a free ware software called "pixInsight LE"
you can download it for free. http://pixinsight.com/
there are some nice tutorilas that will explain how to deal with the SGBNR fuction, that allows smooth-filter-application specifically, without hurting detail.
all the best and good luck