Hubble Prawn

[troypiggo (Troy)]

Ok, I was just getting this ready to post, then saw Martin's unreal Vela SNR. Nearly didn't bother posting, but will anyway to show how persistent I am

I think I'm getting there with the blending of channels/filters. This is straight SII in red, Ha in green, and OIII in blue, but I found I had to boost the SII and OIII by 7.5 times the Ha to get the nebulosity to start showing some blues and yellows instead of all green. I just did this with PixelMaths. No playing with channels or hues afterwards. Obviously, because of boosting the R and B channels so much, the stars go that magenta colour and it's very apparent why they're always these colours in the Hubble images. I might go back and try to figure out how to blend in stars a bit more natural coloured with PixInsight.

Probably not the best image scale for this target, but it was in the right part of the sky at the right time.

Comments/critiques/advice very welcome please.

[Ross G]

Great effort Troy.

You've brought out some nice detail.


Ross.

[multiweb (Marc)]

Cool! I'm working on a NB widefield of this one as well. Looks like so far I have he same colors you got. Nice one

[troypiggo (Troy)]

Thanks guys. Looking at this again, the stars do kinda spoil it, don't they. Need to figure this out.

[multiweb (Marc)]

Originally Posted by troypiggo

Thanks guys. Looking at this again, the stars do kinda spoil it, don't they. Need to figure this out.

I find that if you get the stars from the 1:1:1 blend when everything else is green you get good star colors. Then you push your colors and the last step do a Reduce Noise in PS. That whites out all the stars then put the Original stars as color and you get rid of all the pink bits.

[strongmanmike (Michael)]

The Prawn colours are lovely, deal with the stars and you will have a great shot there

Never let other images put you off from posting

"Every eye is an eye, when you're doing the surgery there that is just as important as if you were doing eye surgery on the prime minster or the king."

Mike

[h0ughy (David)]

the prawns a tad green but then its not over cooked - fantastic, love what you have got

[RobF (Rob)]

Yep, keep posting please Troy. Not a hint of spamming here - we're all astro tragics hanging out for the next fix remember!

Like how the image has come together, and info on relative stretches vs Ha interesting. Does that mean we should be collecting 7 times as much SII and OIII than Ha?

[troypiggo (Troy)]

Thanks mate. That's what I'm experimenting with. Wondering if it's 7 times longer subs (or some fraction of that), or 7 times as many subs of same length.

[RobF (Rob)]

I guess the other way of attacking it might be some sort of numeric estimate of signal to noise ratio. Then use usual means to get sufficient SNR for SII and OIII vs Ha (dependent on skyglow coming through bandpass for each filter, exposure length, total exposure time, value of Drachma, etc!)

[multiweb (Marc)]

Originally Posted by troypiggo

Thanks mate. That's what I'm experimenting with. Wondering if it's 7 times longer subs (or some fraction of that), or 7 times as many subs of same length.

Originally Posted by RobF

I guess the other way of attacking it might be some sort of numeric estimate of signal to noise ratio. Then use usual means to get sufficient SNR for SII and OIII vs Ha (dependent on skyglow coming through bandpass for each filter, exposure length, total exposure time, value of Drachma, etc!)

I suspect that good enough is just that. If you have enough SNR with your Sii and Oiii to stretch without bringing up too much noise in those channels then you can bring up their levels to your Ha. Or meet half way. Lower the Ha and reach up with Sii and Oiii. Regardless of what colour your original blend turns out to be, which is mostly green anyway, your ability to bring up the colors Red and Blue from the other channels will only depend on how much data quality data is in there. Not its strength. If it's not noisy and you have a reasonable SNR then it's good enough IMHO.