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[RCC] Would love some constructive critique on this processing!

Adobe Photoshop Request for feedback M43 Deep Sky
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Pedro Guerreiro avatar
Pedro Guerreiro avatar
This is my first time posting here and I would love to see some feedbacks and tips. I took the data from the Hubble Space Telescope archive. 

I mostly tinkered with levels, curves, saturation and hue in photoshop. Did some noise reduction and sharpening as well (nothing too much because i don't know what are the best settings etc)



M43 - De Mairan's Nebula ( Pedro Guerreiro ) - AstroBin
andrea tasselli avatar
andrea tasselli avatar
Frankly difficult to say without knowing what you were trying to achieve. Is it supposed to be a RGB (natural colours) image? In which case the colours are rather wrong, certainly for the stars. Difficult to do with a HST data set anyway so maybe not the best place to start. Probably clipped the shadows as well and very plasticky look of the hi-res image, showing an excess of median filtering. Plus odd bits of cosmic ray hits here and there.
Pedro Guerreiro avatar
Pedro Guerreiro avatar
andrea tasselli:
Frankly difficult to say without knowing what you were trying to achieve. Is it supposed to be a RGB (natural colours) image? In which case the colours are rather wrong, certainly for the stars. Difficult to do with a HST data set anyway so maybe not the best place to start. Probably clipped the shadows as well and very plasticky look of the hi-res image, showing an excess of median filtering. Plus odd bits of cosmic ray hits here and there.

Thanks for the reply! Sorry for not making it very clear but I took more of an "artistic" approach and just used colors I thought were pretty. I would like to know more about the shadow clipping issue and the cosmic ray hits, how could I fix that? Thx so much in advance!
andrea tasselli avatar
andrea tasselli avatar
Ah, ok. I still think it would be better to have the stars with more natural colours even in the context of quasi-narrowband imagery. Aesthetically they are more pleasing to the eye and since you already separating the stars from the nebula you might as well do it (in Siril for example). As for clipping the shadows it depends where you cut the histogram when converting from linear to non-linear and what have you used to do that. As the whole area is awash in radiation, gas and dust it stands to reason not to expect to be any pitch black areas in there. In other words there needs to be showing some level of gray (if the background is set to neutral) on the whole of the image. I don't have the set myslef so I cannot replicate the image with a different processing. As for the cosmic ray hits the best way is to rubber-stamp them with nearby areas without the hits, with some form of blending depending on the strength of the hits. Sizewise I'd say around 5 pixels would do.
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