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Elephant Nebula

Posted: Thu Aug 22, 2019 2:52 pm
by Rkonrad
Again, this is not my own data - but "BigScott27",s from https://www.astrobin.com/rawdata/publicdatapools/63/. This is a hubble narrow band process. Very briefly, I processed each Ha Oiii, and Sii individually. I recombined them processed - under LRGB without tracking to get the colours (Sii=red, HA=green and Oiii=blue). Then I removed the stars of the binned image and replaced it with the stars of the original high resolution unbinned data. The online Photopea https://www.photopea.com/ helped me to get the colours altered to a traditional Hubble palette (under "image-adjustments-selective colours). The method is here http://little-piney-observatory.blogspo ... mages.html. I'm not sure if this is what the Hubble team actually did or if it's is a personal method?

I processed this on a first generation dual core computer (super slow) so had to immediately bin the files to default. My experience, so far, is if I bin the data (very good data) too soon I lose a lot of fine nebulosity and here, the result is an image that is somewhat more "contrasty" than I would like. Nevertheless, I'm fairly happy with it.

https://www.flickr.com/gp/rkonrad/70a02g

Richard

Re: Elephant Nebula

Posted: Sun Aug 25, 2019 4:26 am
by admin
Hi Richard,

The Compose module should be what you're after; it allows you to process color and detail in parallel, making processing of complex datasets (almost) as easy as DSLR datasets.
Processing color channels separately is fraught with danger in terms of creating detail that doesn't really exist (see also this post on CloudyNights).

A new video was released showing how to process SHO datasets. You can pretty much replace the used dataset in that video and use your own (with parameters tweaked to your taste of course);
https://www.youtube.com/watch?v=-Xj-tbgQ2Fs

I had a quick look at the dataset in question. You should be able to get Hubble-esque coloring fairly easy using the Hubble preset and perhaps bump up the Green Bias Reduce to reduce green and bring out more yellow.

Hope this helps!