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Home Forums Observing and Imaging Group M42 Processing

This topic contains 5 replies, has 3 voices, and was last updated by  Astrograph 2 years, 8 months ago.

Viewing 6 posts - 1 through 6 (of 6 total)
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  • #14908

    Astrograph
    Participant
    Topics: 27
    Replies: 102

    I have been playing with an image of M42 I took in December and trying to improve my knowledge of Photoshop in the process(!).

    The image was taken with a Moravian G2-8300 (micro 4/3 size) using LRGB filters using a Tecnosky 100/580 Flat Field Refractor.

    The L Luminence channel was a CLS light pollution filter instead of a normal UV/IR cut because light pollution is so bad in SE London. The original images taken were;

    10 x 60 sec, 120 sec, 240 sec and 480 sec Red, Green & Blue

     

    10 x 60 sec and 120 sec Luminance.

    Then 10 x Flats, 10 x Dark Bias and 10 x 120, 240 and 480 sec Darks.

    I made an HDR of each RGB image but excluded the 60 sec images because the core was already dark enough.

    So this was my first attempt

    M42 December 16 by Rupert Smith[/url], on Flickr

    I was sort of OK with this but notice the big gradient of light pollution coming in from the bottom right. I was also convinced there was more to get out of it. Asking around and fumbling in Photoshop I discovered that going to Image / Adjustment / Equalize will show you just how much data is in an image. Very useful, but I just did not know how to get there. In the end the other most useful tool I found was a filter plug in called GradientXTerminator. Lot of big names use it. Once I learnt how it works it fixed the trouble. Another good filter plug-in is the Nix software suite which is now free as Google bought it. Its like having another software program inside PS.

    So after lots of careful stretching, gradients, enhancements, star masks and layers and layers I have got to this.

    M42 December 16 170116 by Rupert Smith[/url], on Flickr

    Got some noise coming through now but the main aim was to bring out the cloud without burning out the background and learn something. For others that wish to learn something then I also recommend the book ‘Lessons from the Masters’ as its full of useful bits.

    I think more data from somewhere better is the next step plus some more PS practice.

    #14910

    Andy Sawers
    Moderator
    Topics: 126
    Replies: 602

    Stunning! Can definitely see a difference. You’re starting to get pretty good at this, Rupert 😉

    It looks like there’s a man’s face emerging from the nebula in the middle of the left-hand edge!

    #14911

    Andy Sawers
    Moderator
    Topics: 126
    Replies: 602

    Here’s my image of M42 with the Crab Nebula, Butterfly cluster and globular cluster M5.

    #14912

    Astrograph
    Participant
    Topics: 27
    Replies: 102

    Very Funny, and well captured considering it was daytime.

    You must be one of those folks that likes to see things in clouds. The ‘face’ as you put it is known as the ‘Running Man’ Nebula, or to my son’s eye, the ‘Gingerbread Man’

    Thanks for the compliment but if you had seen the book I mentioned you would realise I am at stage zero.

    Whoever edited it and arranged the chapters clearly wanted to put people off as the second page states;

    ‘Poisson noise is caused by random variations of quantum accumulations and exhibits a mathematical predictability. The uncertainty of an accumulation of random discreet events is described by;

    (fancy formula)’

    Went on like that for another 26 pages. I think I probably have some of this stuff in my picture….

     

    #14916

    Clive Inglis
    Participant
    Topics: 17
    Replies: 41

    Wow! A superb image. Are you sure you haven’t got anything in orbit? Thanks for sharing it.

    #14917

    Astrograph
    Participant
    Topics: 27
    Replies: 102

    Now there’s an idea! Small Scope + Weather Balloon + Large Firework might get us up there….

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