Astro Pixel Processor

Ha, OIII, SII stacking, how to?

Viewing 15 posts - 1 through 15 (of 38 total)
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  • #12740

    Musquetier
    Participant
    posts: 437

    I have loaded all the Ha, OIII and SII lights together with the 3 Ha, OIII and SII master flats, a master dark and a master bias. Then calibrated, analysed stars, registered all frames, normalized them and then pressed stack but then I end up with a single gray image. Should I process each color separately instead?

    #12746

    Groenewold
    Moderator
    posts: 1098

    I think, as I also struggled a little bit with H-alpha, you better process these seperately and choose the mode in tab 0. Standard it says “Airy Disk” there, but there’s options for HAlpha etc.

    #12747

    Musquetier
    Participant
    posts: 437

    When I progress them separately how do I make sure they are aligned correctly (during the registration phase)?

    #12759

    Haverkamp
    Participant
    posts: 641

    I think Rob is working with mono channel data, then the Halpha debayer mode is useless @supernov.

    Yes, process the channels seperately Rob. Registration can be simply done when you have the stacks ready. Just load the stacks and register them and save registered frames.

    Or another way.

    Calirbate all you lights first and save your calirbated lights. Then load all lights of all channels and register them. And save registered frames.

    Then you can stack all channels separately using registration mode: no registration

    There are several ways to do this.

    In the future, we can try to make a batch mode tool for this, I believe Yves mentioned this to me already 😉

    #12768

    Van den Broek
    Participant
    posts: 97

    Why would one need to select mode: no registration when you only stack, I even don’t see it in the stack tab, probably a blind spot.

    #12777

    Haverkamp
    Participant
    posts: 641

    Hi Yves, the no registration mode is to be set in

    4) Register, registration mode: no registration.

    APP is unlike PI, it is setup to do all steps

    2) to 6) all in one go. So Registration is always a logical part of a stack process. If you have registered the data already, you want to use no registration mode.

    My logic: if you don’t implement it like this, you’ll need to save your frames always after registration. Before starting a stack proces. I actually never save registrered frames as part of a normal stack routine.

    #12842

    Musquetier
    Participant
    posts: 437

    Ok, I have now a R, G, B, Ha, OIII and SII stack, all registered to one master, but they do differ in size because they are all taken on different days (in 2016 and 2017) and with two different camera’s which were mounted using a different rotation.

    What is the procedure in APP to make them all similar without loosing the alignment, (so without shifting them on the X and Y axles).

    Can this also be done in APP as well so I have done the complete processing using only this application?

    Once this is done I can do the Combine RGB option in the 9) TOOLS tab to transfer to color and do the final tweaks…

    #12874

    Haverkamp
    Participant
    posts: 641

    Hi Rob, best way would be to load all of your stacks and register them again. I see I forget a dropdown down box at save registered frames, I will fix this now.

    When you have registered them,

    go to 6) integration, set composition to full  and click on apply mode.

    If you then click on save registered frames, wou won’t lose data and all frames will have the same image dimensions.

    I need to create the dropdownbox for composition at save registered frames.. Will do it now.. ?

    Let me know it it works ?

    And if it works, then proceed to combine RGB indeed ? and possibly selective color afterwards for finetuning of the colors.

    The combine RGB will adjust for illumination differences to start with ? so the background of your different channels will almost be perfect to start with.

    #12990

    Musquetier
    Participant
    posts: 437
    #13002

    Haverkamp
    Participant
    posts: 641

    Ik zal even testen wat er gebeurd, dank je Rob

    #13008

    Haverkamp
    Participant
    posts: 641

    Hoi Rob, de Ha data heeft geen data, dat is het probleem. Bekijk hem maar met bijvoorbeeld Fits Liberator of PI. Ik zie dat je combined als prefix ervoor hebt gezet

    combined_Barnard33_Ha.fits

    Heb je toevallig de stack nog liggen, ik denk dat er na het stacken iets is misgegaan. De andere opnames hebben wel sterren, zie screenshot.

    #13009

    Haverkamp
    Participant
    posts: 641

    Het is denk ik handig om te weten wat je met de OIII en HA stacks hebt gedaan om naar de combined versie te komen?

    Het lijkt alsof die ook door een ander programma een bewerking hebben gekregen. Ik zie namelijk ook de de OIII moeilijk te registreren is, wat er op wijst dat een ander programma iets van een registratie heeft gedaan met mogelijk een slecht effect ?

    #13022

    Musquetier
    Participant
    posts: 437

    The combined file should have been a stack of the following files (2016 (PI) and 2017 (APP) data):

    https://www.musquetier.nl/images/Barnard33_light-FILTER_Ha-BINNING_1-reg.fits
    https://www.musquetier.nl/images/stack_Ha.fits

    I’m not sure why it turned out to be black.

    #13025

    Haverkamp
    Participant
    posts: 641

    I’ll have a look 😉

    #13027

    Haverkamp
    Participant
    posts: 641

    I can integrate these two images fine:

    What I did:

    Since there aren’t too many stars ( 100-200) I lowered kappa in the star analysis to 4

    3) analyse stars ,

    detect above noise

    kappa 4

    4) registration

    since this is data from Pi and data from APP, clearly different sources, you need to

    deselect same camera and optics ( a registration tool from a program is in technically speaking also a camera, it warps your data )

    and

    enable distortion correction

    Then

    5) normalize, I set normalization mode to advanced ! This will have the effect that the normalization parameters are only calculated on the area of the stacks that overlap. This will give better data normalization in this case ( this is one of the innovative feautures in APP).

    6) Integrate

    – composition mode FULL, we wwant to keep all data of both stacks in the final stack

    – LNC set to 2nd degree, 3 iterations

    – enabled MBB 10%

    -Lanczos3 with no under/overshoot

    and then stacked

    The result is shown in the screenshot, notice that the seams of the stacks are hardly visible now..

    So you can also do this with the OIII combine you did ?

    Let me know if you can duplicate this result on the H alpha combination of the 2 stacks.

Viewing 15 posts - 1 through 15 (of 38 total)

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