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RCC from a new-to-mono imager

LRGB Monochrome Request for feedback
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Vin avatar
Vin avatar

Hello,

I’ve just finished setting up my first ever remote imaging setup at a new obs in SA. I normally image in Bortle 9 so dualband OSC has been my modus operandi. But for these beautiful sky conditions, I’ve taken the plunge into mono imaging.

This is my second ever mono image: https://app.astrobin.com/i/bl65xf so I would welcome all constructive feedback pls!

The workflow I followed was calibration and then stacking in APP. After which over to PI with BXT (correct only) on each of the L R G & B.

Then star alignment and linear channel combination to get an RGB.

SPFC on both L & RGB, and SPCC on the RGB.

Then separate stretches on the L & RGB - in each of those, I separated stars from starless and stretched those before image blending them back.

Then non-linear LRGB recombination.

All comments on either the workflow, or ofc the aesthetics, are welcome.

I am seriously blown away by the quality and colours of dark skies.

Thank you!

Vin

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andrea tasselli avatar
andrea tasselli avatar
It looks pretty washed-out, like bleached out of its true colors. Given the small scale you need to push up contrast a bit more too.
Vin avatar
Vin avatar

andrea tasselli · Nov 29, 2025 at 01:17 PM

It tools pretty washed-out, like bleached out of its true colors. Given the small scale you need to push up contrast a bit more too.

Thanks Andrea. Can I ask what you mean by bleached/washed-out of true colours? For the colours I just used SPCC and did not change the colour curves other than that - so I would have thought SPCC would return the true colours? (The ratio I used for L:R:G:B was 2:1:1:1). Thanks!

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andrea tasselli avatar
andrea tasselli avatar
Well, I would expect more vibrant colors than what I see there. It isn't as much as the basic color shades themselves but how vibrant they look. Intrinsically, LRGB tends to wash out colors if you aren't careful. I like to use 1:1:1:1 whenever I can and I feed the RGB back into the L so I get also better matching between L and RGB.
Rick Krejci avatar
Rick Krejci avatar

Vin · Nov 29, 2025, 04:37 PM

andrea tasselli · Nov 29, 2025 at 01:17 PM

It tools pretty washed-out, like bleached out of its true colors. Given the small scale you need to push up contrast a bit more too.

Thanks Andrea. Can I ask what you mean by bleached/washed-out of true colours? For the colours I just used SPCC and did not change the colour curves other than that - so I would have thought SPCC would return the true colours? (The ratio I used for L:R:G:B was 2:1:1:1). Thanks!

Like Andrea said, Luminance layering can lead to very unsaturated colors if you aren’t careful. You need to match the histogram of the L with the RGB before combining.

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Vin avatar
Vin avatar

Thanks both @andrea tasselli & @Rick Krejci - ok I think I understand what you mean then. Will try that! Cheers