NGC40 done with Sigma-Clip

Discussion in 'My Astrophotos' started by ROBERT T SCHAEFER JR, May 3, 2019.


    ROBERT T SCHAEFER JR Cyanogen Customer

    May 13, 2018
    CanonEOS RebelT7i 'mod. UV-IR @ Hutech' using a TeleVue 2.5XPowerMate into a 2XPowerMate
    for 5900mmF/L for 34-RAWMonochrome Autosaves thru MaximDL Pro V6.16 on an
    Astro-Physics 1200GTO Mount for 125secISO6400 images and 'calibrated' in MaximDL Pro ... from a
    Bin2 size and the data contained with the 'screen-stretch' carots without 'clipping and data I used t
    he 'Stretch' command for 12BIT(4095) on each image and saved them that way and then I Sigma-Clip stacked
    them with SigmaFactor 0.5 and Normalization: 50% without any IgnoreOver and the images were
    Astrometric Align ... and the end result Max-Val was 0-2200 and the Log said 99% of the pixels were
    'clipped' .... here is a copy of the Log that I pasted in :
    MaxIm DL Version 6.16 started on DESKTOP-QCLR41U
    Process, Stack
    36 files added in 1 group (new) [2.34 sec]
    View, Zoom In: [Reference image]
    View, Zoom In: [Reference image]
    Added 34 images for NGC40 [17.66 sec]
    Sigma Clip factor 0.50: clipped 99.5% (5821803 of 5849907 pixels)
    Sigma Clip combine succeeded using 507960KB memory [3.27 sec]
    Process, Stack (OK)
    View, Zoom In: NGC40
    View, Zoom In: NGC40
    View, Zoom In: NGC40
    Screen Stretch "Max Val", NGC40
    View, Log Window
    - this shows that this stacking method decreased the images's Max-Val 0-4095 to 0-2200 ????? .-
    I then put the Max-Val 0-2200 FITS as IEEEFloat into "ImagesPlus" and worked on it … mainly on the bright
    'center' star which I used the "Stretch" command 'Brightness and Conrtast' with the 'Minimum' slider 'checked'
    and I left-clicked on the 'center' star which slid to a high value and the slid the 'Brightness' slider all the way to
    the right for full brightness and then I moved the 'Minimum' slider to the point the showed the star to be small
    and at it's brightest point . Then in the 'Pixel Math' command I did the same thing with the sliders and
    increased the 'Multiply' option to brighten the small 'center' star … and after that some darkening of the
    background sky .x

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