Page 1 of 2 12 LastLast
Results 1 to 10 of 18
Like Tree4Likes

Thread: Help on Processing

  1. #1
    astronomynut's Avatar
    astronomynut is offline HYPER GIANT
    Points: 24,637, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Jan 2014
    Location
    Twentynine Palms, California USA
    Posts
    2,940
    Points
    24,637
    Level
    100
    Thanks
    131
    Thanked 478x 440 Posts
    Blog Entries
    3

    Default Help on Processing



    I've been taking many pictures of open and globular star clusters this summer. I am doing this due to the heat. Keeping exposures at two minutes, hopefully will help me from destroying my camera sensor.

    My biggest problem seems to be processing globular clusters, but some of the open clusters are also give me the yips. My primary processing tool has been StarTools. I have had some very nice picture come out of my efforts, though I am starting to believe some were just dumb luck.

    My question is, What should the histogram look like. As far as I know, it should be to the left. Should all the colours line up?

    I see results on Astrobin with histograms having a very narrow base, and going to a spike, and I also see others that have a wider base, and more of a curved peak, sometimes not all colours being aligned.

    I am guessing that you can get brighter colours with more saturation.

    Another program I use is GIMP, and have only started using it because I have had difficulty getting anything to look nice from StarTools.
    In GIMP there is a section under Colours that is called Levels. It has an input and output section. The input has three pointers that you drag, and the output has just two. What exactly do these sliders do. I think someone once told me something about black point, or some such. I have noticed when manipulating this part that the background tends to either lighten or darken when using the far left pointer of the input.

    Anyway, I just cannot put time, anywhere from 50 to 300 minutes worth of exposure data, and keep coming up with junk. I see too many wonderful results from people basically using the same equipment, and have to know I am goofing things up in the processing. I figure that hitting you with a few questions here and there may help me progress to the next level. Thanks Caley
    Caley Ann
    Explore Scientific ES102ES and TPO RC 8 inch; Celestron AVX and Celestron CGEM DX mounts; Canon 3Ti, and 7D mkII, and ZWO ASI 174MC and 1600MM cooled; Orion Stratus (68*) 21, 17, 13, 8, 5, 3.5MM, Q70 26, 32, 38MM ; Orion 80mm ST and MMAG; ATIK EFW 1.25

  2. #2
    KathyNS's Avatar
    KathyNS is offline Super Moderator
    Points: 172,997, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 53.0%
    Achievements:
    200+ Posts Achievement!Ghost Achievement! Averaging 5+ posts a day!First 1000 Experience Points400+ Posts AchievementGot three Friends
    Awards:
    Reply Award
    Join Date
    Nov 2010
    Location
    Nova Scotia
    Posts
    25,170
    Points
    172,997
    Level
    100
    Thanks
    6,659
    Thanked 14,983x 9,541 Posts
    Blog Entries
    3

    Default Re: Help on Processing

    Quote Originally Posted by astronomynut View Post
    In GIMP there is a section under Colours that is called Levels. It has an input and output section. The input has three pointers that you drag, and the output has just two. What exactly do these sliders do. I think someone once told me something about black point, or some such. I have noticed when manipulating this part that the background tends to either lighten or darken when using the far left pointer of the input.
    I have seen your astrophotos, and they look good, so you must already know about histogram stretching. I don't know what terminology Star Tools uses, but the Levels tool in GIMP is the histogram stretching tool.

    The left slider is the black point. Any pixels darker than the black point will be rendered as black, even if they weren't originally black. If there is data in that region, this is called clipping, because that data will be destroyed. The proper use for the black point is if there aren't any pixels that dark. Those levels are therefore unused, and moving the black point makes that part of the dynamic range useable.

    Same thing with the right slider, which is the white point. Any highlights brighter than the white point will be rendered as white. You use the white point to recover unused dynamic range at the bright end of the histogram.

    The middle slider is the mid point. Pixels at this level will be rendered as medium brightness. Pixels between the black point and the mid point, and between the mid point and the white point are interpolated to maintain a smooth brightness gradient.

    I have no idea why there are output level sliders. I can't think of any reason why you would want the output range to be anything other than 0-255.

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    DSO AP:
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Newtonian Astrograph; ATIK 383L+; EFW2 filter wheel; Astrodon Ha,LRGB filters; KWIQ/QHY5 guide
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    ; Planetary AP: Celestron C-11; ZWO ASI120MC; Portable: Celestron C-8 on
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    pro; C-90 on wedge; 20x80 binos; Etc: Canon 350D; Various EPs, etc. Obs: 8' Exploradome;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    (pier);
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    .

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  3. #3
    astronomynut's Avatar
    astronomynut is offline HYPER GIANT
    Points: 24,637, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Jan 2014
    Location
    Twentynine Palms, California USA
    Posts
    2,940
    Points
    24,637
    Level
    100
    Thanks
    131
    Thanked 478x 440 Posts
    Blog Entries
    3

    Default Re: Help on Processing

    Keith, I think I've got that. If I move the left cursor a little to the right, I am going to clip out some of the black. The same thing basically happens with the right cursor clipping things as you move it left. That is why I see darkening and lightening when I move these. I really haven't noticed anything significant when moving the center cursor either way.

    Thanks for the kind words on my photos. I know I still need to improve the processing. I am trying to get the red stars and blue stars, or are those blue actually white?, to get a deeper colour. Right now I end up with pale stars that just look sick compared to what others have achieved. Seems each time I try to enhance the colour, I end up with way too much, or too little, when I just want them just right.

    I'll keep playing with this part of GIMP until I learn it. One piece of the puzzle at a time. Caley
    Caley Ann
    Explore Scientific ES102ES and TPO RC 8 inch; Celestron AVX and Celestron CGEM DX mounts; Canon 3Ti, and 7D mkII, and ZWO ASI 174MC and 1600MM cooled; Orion Stratus (68*) 21, 17, 13, 8, 5, 3.5MM, Q70 26, 32, 38MM ; Orion 80mm ST and MMAG; ATIK EFW 1.25

  4. #4
    kingclinton's Avatar
    kingclinton is offline Super Moderator
    Points: 100,009, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 7.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Nov 2012
    Location
    Earth
    Posts
    16,175
    Points
    100,009
    Level
    100
    Thanks
    6,423
    Thanked 6,705x 4,378 Posts

    Default Re: Help on Processing

    Caley here is a link that helps explain how to get the colour from your stars.

    LINK:StarTools • View topic - Mel 15

    This was posted by Hondo in the Star tools group here:StarTools software - Astronomy Forums | Telescope Forums & Reviews | Astronomy Community

    It might help a little.
    I just started using star tools and it is an amazing program.
    I think the "Levels" tool in star tools is develop/auto develop. I have found only using the develop module is much better and I have the control over the dark and light points.

    Cheers
    .

  5. #5
    astronomynut's Avatar
    astronomynut is offline HYPER GIANT
    Points: 24,637, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Jan 2014
    Location
    Twentynine Palms, California USA
    Posts
    2,940
    Points
    24,637
    Level
    100
    Thanks
    131
    Thanked 478x 440 Posts
    Blog Entries
    3

    Default Re: Help on Processing

    Clint, Yes, Once I got used to the program, I occasionally got some very satisfying results. But they have been far and few between.

    I also find that using "develop" is the best route for stretching things. "auto develop" is just too aggressive, making further processing very difficult.

    Hondo has produced some of the best photos I have ever seen. So that link will probably get me another step closer to understanding more about StarTools. Thanks Caley
    Hondo and kingclinton like this.
    Caley Ann
    Explore Scientific ES102ES and TPO RC 8 inch; Celestron AVX and Celestron CGEM DX mounts; Canon 3Ti, and 7D mkII, and ZWO ASI 174MC and 1600MM cooled; Orion Stratus (68*) 21, 17, 13, 8, 5, 3.5MM, Q70 26, 32, 38MM ; Orion 80mm ST and MMAG; ATIK EFW 1.25

  6. The Following 2 Users Say Thank You to astronomynut For This Useful Post:

    Hondo (08-17-2015),kingclinton (08-16-2015)

  7. #6
    CamelHat's Avatar
    CamelHat is offline Bronze Supporter
    Points: 52,105, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    50 Posts Achievement!5 Threads Achievement!First 1000 Experience Points2 Posts Achievement20 Posts Achievement!
    Join Date
    Dec 2011
    Location
    Santa Barbara, CA
    Posts
    5,807
    Points
    52,105
    Level
    100
    Thanks
    1,170
    Thanked 1,719x 1,387 Posts

    Default Re: Help on Processing

    Do you use DSS for stacking, and if so, do you load your image straight from DSS into Gimp? That could be a source of trouble because Gimp is 8 bit. In that case edit it in some other 16 or 32 bit editor first until the color balance, contrast and saturation looks roughly right then load it into Gimp. I have used Gimp and know it fairly well but I sometimes get lost in the many controls that it has, some of which do the same in a different way. I find DSS by far the easiest to use preprocessing editor. Sometimes nothing more is needed. Having seen many StarTools pictures I find that the color balance is off with many of them, that the saturation is often too much and that sometimes colors get clipped. Then again I have also seen very good results from StarTools so I suppose it is a matter of going through a learning curve that is not always clear to everyone.
    ... Henk. Telescopes: 6" Mak-Newt (Comet Hunter), ES ED127CF, ES ED80, Zhumell Z12, Coulter Odyssey 10, AT6RC, Venture RX-7, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S, AVX, LXD55, Tiltall, Cameras: Fuji X-a1, Canon SX40, Xt, XSi, T6, ELPH 100HS, DIY: Dob and camera barndoor trackers, afocal adapter, Dob with foldable base and Az/Alt setting circles, Accessories: SSAG, Plossls, Barlows, Telrad, laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: DSS, ImageMagick, PHD, Nebulosity, Photo Gallery, Gimp, CHDK

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  8. #7
    lenrough's Avatar
    lenrough is offline Main Sequence
    Points: 4,954, Level: 48
    Level completed: 2%, Points required for next Level: 196
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!First 1000 Experience Points
    Join Date
    Feb 2015
    Location
    NM
    Posts
    113
    Points
    4,954
    Level
    48
    Thanks
    37
    Thanked 43x 30 Posts

    Default Re: Help on Processing

    I found some very good tips on DSS, IRIS, and GIMP in this presentation.

    http://bf-astro.com/wideDSLR.pdf

    Hope it helps!

  9. #8
    astronomynut's Avatar
    astronomynut is offline HYPER GIANT
    Points: 24,637, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Jan 2014
    Location
    Twentynine Palms, California USA
    Posts
    2,940
    Points
    24,637
    Level
    100
    Thanks
    131
    Thanked 478x 440 Posts
    Blog Entries
    3

    Default Re: Help on Processing

    I just browsed those links. Good stuff there, but it is really for those who are processing data from a Mono CCD camera in LRGB, etc. I've seen the layer part of StarTools, but have never used it because I didn't understand it. Now I know it is a good too for mono cameras.

    I think I need to concentrate on lining up the histogram in StarTools, then going into GIMP to adjust things and stretch, at least when it comes to open and globular star clusters. Lots of experimenting and learning to do when it comes to processing. Caley
    Caley Ann
    Explore Scientific ES102ES and TPO RC 8 inch; Celestron AVX and Celestron CGEM DX mounts; Canon 3Ti, and 7D mkII, and ZWO ASI 174MC and 1600MM cooled; Orion Stratus (68*) 21, 17, 13, 8, 5, 3.5MM, Q70 26, 32, 38MM ; Orion 80mm ST and MMAG; ATIK EFW 1.25

  10. #9
    astronomynut's Avatar
    astronomynut is offline HYPER GIANT
    Points: 24,637, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Jan 2014
    Location
    Twentynine Palms, California USA
    Posts
    2,940
    Points
    24,637
    Level
    100
    Thanks
    131
    Thanked 478x 440 Posts
    Blog Entries
    3

    Default Re: Help on Processing

    Henk, I have everything set in the camera for unmodified RAW images. I upload these in DSS, again making sure no processing is done in DSS. StarTools like unmodified RAW data. Only after I have saved my finished version from StarTools do I move the TIFF image to GIMP. I am still learning how things work in both programs. I am a very slow learner when it comes to complex things, but once something clicks, I can usually do things quite well. So far nothing has clicked for me. Probably just not enough understanding of all the modules in both programs. Caley
    Caley Ann
    Explore Scientific ES102ES and TPO RC 8 inch; Celestron AVX and Celestron CGEM DX mounts; Canon 3Ti, and 7D mkII, and ZWO ASI 174MC and 1600MM cooled; Orion Stratus (68*) 21, 17, 13, 8, 5, 3.5MM, Q70 26, 32, 38MM ; Orion 80mm ST and MMAG; ATIK EFW 1.25

  11. #10
    astronomynut's Avatar
    astronomynut is offline HYPER GIANT
    Points: 24,637, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!Blogger Achievement!
    Join Date
    Jan 2014
    Location
    Twentynine Palms, California USA
    Posts
    2,940
    Points
    24,637
    Level
    100
    Thanks
    131
    Thanked 478x 440 Posts
    Blog Entries
    3

    Default Re: Help on Processing

    Len, That looks pretty good. I put a copy in my computer folder on AP. Thanks Caley
    Caley Ann
    Explore Scientific ES102ES and TPO RC 8 inch; Celestron AVX and Celestron CGEM DX mounts; Canon 3Ti, and 7D mkII, and ZWO ASI 174MC and 1600MM cooled; Orion Stratus (68*) 21, 17, 13, 8, 5, 3.5MM, Q70 26, 32, 38MM ; Orion 80mm ST and MMAG; ATIK EFW 1.25

 

 
Page 1 of 2 12 LastLast

Similar Threads

  1. Getting better at processing
    By Slymin in forum Astrophotography Forum
    Replies: 21
    Last Post: 12-20-2013, 06:48 PM
  2. M31 processing
    By whammond in forum Astrophotography Image Processing Forum
    Replies: 18
    Last Post: 07-19-2013, 12:09 AM
  3. New to Processing
    By pleiades6 in forum Astrophotography Image Processing Forum
    Replies: 1
    Last Post: 03-05-2012, 03:59 AM
  4. M42 Processing
    By dusterg20 in forum Astrophotography Forum
    Replies: 10
    Last Post: 01-08-2012, 07:21 AM
  5. CCD processing
    By Karsten Schulz in forum CCD Imaging Forum
    Replies: 0
    Last Post: 08-09-2006, 10:27 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 09:59 AM.