Hue Adjustment [PixInsight Tutorial]

[@rickbria8420]

Thanks Paul, well done! Hue is some thing I don’t use, but it’s clear I’m missing out. Thanks for this demo, I will give it a try in my images.

[@PaulymanAstro]

It is not something I touch when processing LRGB or “traditional” SHO type images. But once into the realm of alternative palettes it’s open season. It is very easy to have a heavy hand with it so keep that in mind.

[@danjensen9425]

Awesome , I just ran into The mystic mountain a few weeks ago in two versions. Knowing I can get the data is great but I’ll wait till my skills catch up. Just got into narrowband so lots of learning ahead . Nice video thank you.

[@PaulymanAstro]

Thanks Dan. It’s the first time I’ve played with Hubble Data, it’s definitely interesting to work with. Narrowband is addictive.

[@gordonahooper]

Thanks Paul. Great insight into a tool we use a lot. CT seem to to be limited only by our imagination. I shoot OSC broadband also in the Southern skies. There have been some good videos recently on transforming narrow band OSC to other palettes like Hubble. I am interested to know your thoughts on the topic - especially on how to breath palette interest into OSC broadband. Perhaps a video topic? Best, Gordon in South Africa.

[@PaulymanAstro]

Thanks Gordon. OSC and OSC narrowband is definitely something on my mind. I do have a OSC that I use with a Canon lens, once the weather fines up I can pop it on top of my main rig to get some data and do some videos about it.

[@christopherboyd6537]

Goddamn, you make this look so easy! I’m struggling with my own NB data on Carina at the moment, attempting to use GHS / foraxx. When you say you used GHS to stretch them to ‘get the same intensity’, what do you actually mean? Do you mean you have similar black points, white points and the main histogram peak is at the same level?

[@PaulymanAstro]

Thanks Christopher, I’ve had lots of practice thanks to a cloudy and rainy year. Exactly like you said. Most of the time I do a gentle initial stretch to each to get them all to roughly the same black point and the median of the peaks to be in roughly the same spot. I usually do this step so the Ha channel looks to my liking and then can manipulate the oiii and sii to match, this often means my oiii and sii are quite faint because they are weaker channels from an snr standpoint. So they all have similar backgrounds at this point which is important so when combined there isn’t a colour cast in the background but at this stage the medians of the histograms match but the oiii and sii will probably be very skinny still. So then I remove the stars and work on the weaker oiii and sii to also try and get the histograms stretched out to better match the ha channel in median but also range. I usually just don’t have the snr in my oiii and sii to do this as well as I’d like but the more you can stretch them out the better the colour contrast you will get in the final image. That way they all end up with a similar background levels and the histograms are as similar as I can get them, which produces a similar overall brightness and contrast but with a fair whack of noise in the oiii and sii channels but that’s okay they are used for the RGB and the good less noisy ha channel can be used for luminance.

[@christopherboyd6537]

Paulyman Astro thanks so much for this detailed response!