Cygnus Improve

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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Joined: Tue Nov 19, 2019 7:22 pm

Cygnus Improve

Post by Sidartha »

Hi all, i would like to know if it is possible to improve this wide field image of cygnus.

[img] [img]

Calibration fit with DSS Darks/Flats/Bias
[url] ... haring[url]
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Re: Cygnus Improve

Post by admin »


Can you confirm are using these DSS settings? (e.g. with white balancing turned off).

The dataset appears white balanced to me, while the exposure length seems a little too long as well with many stars over-exposing (or perhaps an too high ISO was used?).

Making sure the stellar profiles stay under control by not exposing too long (or using an ISO that is too high), will often allow stellar profiles to be coalesced successfully into point lights better using deconvolution. This may also help somewhat with the chromatic aberration your lens seems to suffer from.

Be careful when using the Shrink module for very dense star fields. It can make your image look "stringy" or "wormy" if stars are not (or cannot be) properly separate in the mask, or are too close together.

If you are trying to de-emphasise stars in extreme wide field images like these, try relying on the Life module's Isolate preset (no particular mask set, e.g. all pixels selected/green).

--- AutoDev
To see what we got (see above)
--- Bin
--- Crop
Remove stacking artefacts.
Parameter [X1] set to [8 pixels]
Parameter [Y1] set to [10 pixels]
Parameter [X2] set to [2992 pixels (-6)]
Parameter [Y2] set to [1980 pixels (-4)]
Image size is 2984 x 1970
--- Wipe
--- Auto Develop
Final stretch. Defaults.
--- Deconvolution
Mask > Auto > Fat Stars > Invert
Parameter [Mask Fuzz] set to [3.8 pixels]
--- Life
Defaults (make sure mask fully set/green)
You could even run this twice.
--- Color
Parameter [Bright Saturation] set to [2.00] to hide problems in the highlights. ... tha_MW.jpg

Hope this helps at all!
Ivo Jager
StarTools creator and astronomy enthusiast
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