fully Blu and Green stars

Stacking program, astrometric (plate) solver, fits file viewer

Brought to you by: han59

fully Blu and Green stars

Forum: General discussions ASTAP

Creator: Bashar

Created: 2024-12-23

Updated: 2024-12-26

Bashar - 2024-12-23

I have strange star colors, all are fully blue or green, I'm using Astro C method colors pls take a look at the attached photos, one is the original light frame and the other is after the test pattern, the staked one shows the same strange colors!

ASTAP Screnshot.jpg

Original light frame.jpg

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Bashar - 2024-12-23

Attached is my staking settings

Settings.jpg

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han.k - 2024-12-24

Hi Bashar,

My inital tought was a wrong Bayer pattern but it looks good. I like to investigate why this happens. Can you share a few of the original frame for testing the stacking? Then I can reproduce the efffect. Maybe M42 red colour has an influence.

Han

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Bashar - 2024-12-25

Dear Han

Appreciate your quick response, I have attached 3 frames taken by Red cat 250mm and ASi533 camera 180s. I have staked them with DSS it gave me natural star color but I liked ASTAP output because it shous less background color noise.

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Bashar - 2024-12-25

one more

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Bashar - 2024-12-25

last one sorry I could not attached them all at the same time

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han.k - 2024-12-25

One image is enough for the moment. Somehow the debayer routine fails to proper balance the colours. This is strange. I need to investigate this further. Can you attach also a dark frame image?

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Bashar - 2024-12-26

Hi Han

Attached one dark frame for the same camera

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han.k - 2024-12-26

Hi Bashar,

The dark did not solve the problem. Somehow the colour balance routine is not working properly for this image . I need to investigate further. I'm not sure I have time for that the next that the next days but I will report back in a week maximum.

Was any light polution filter used?

Han

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han.k - 2024-12-26

I had a look again on my main computer (not my laptop). The bright stars are blue giants and are really blue if your looking to other M42 images on the internet. There are other fainter stars visible with red or white colour. You could set the colour saturation lower as indicated in the attached screenshots. The exposure time 180 seconds is much too long since the center of the stars is fully saturated making recovery of the stars colour difficult. I would suggest for M42 to use 20 or 30 seconds exposure time max. If you really want white stars you could use debayer method astroM but I would not recommend it. Better to try next time a shorter exposure time and set saturation lower. Colour smooth radius maybe from 10 to 15.

Success, Han

Last edit: han.k 2024-12-26

M42, 2024-12-21, 3x180L, iOptron CEM26GEM28HEM27, (CV), ZWO ASI533MC Pro_average.jpg

Untitled1.png

Untitled2.png

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