NGC6559 et al from Ten Chain Hill - Page 2

Elio · #21 12-07-2013, 09:42 AM

A great image of a spectacular area

even more envious of your sky...and what a dream-setup!

Elio

atalas · #22 12-07-2013, 07:33 PM

Rick,top stuff!

RobF (Rob) · #23 12-07-2013, 09:52 PM

Ok. Well, that's moderately amazing now Rick ....

RickS (Rick) · #24 13-07-2013, 07:32 AM

Thanks Elio, Louie & Rob!

strongmanmike (Michael) · #25 13-07-2013, 07:57 AM

Quite a good result Rick of a fascinating area, yes it does look nice and crisp

Mike

RickS (Rick) · #26 13-07-2013, 02:03 PM

Thanks, Mike!

When are we going to see some galaxies from your new AG12 set up? I'm looking forward to that.

naskies (Dave) · #27 13-07-2013, 02:28 PM

Quote:

Originally Posted by RickS

There were some interesting things happening in the processing of the colour data that I still need to figure out. I had to desaturate a couple of times (reduce CIE c* with curves) to prevent white clipping the red and blue channels when I converted to sRGB. Perhaps NGC6559 should be called the out-of-gamut nebula

Strange... did the colours look okay on screen? It sounds like a Relative Colorimetric rendering intent (clips out of gamut colours) was being used instead of Perceptual (this is usually preferred - compresses the image's gamut into the destination gamut).

http://www.cambridgeincolour.com/tut...conversion.htm

strongmanmike (Michael) · #28 13-07-2013, 02:38 PM

Quote:

Originally Posted by RickS

Thanks, Mike!

When are we going to see some galaxies from your new AG12 set up? I'm looking forward to that.

Soon, soon...man, should see my list of potential objects

...now if the weather will just cooperate

....

Mike

RickS (Rick) · #29 13-07-2013, 03:20 PM

Quote:

Originally Posted by naskies

Strange... did the colours look okay on screen? It sounds like a Relative Colorimetric rendering intent (clips out of gamut colours) was being used instead of Perceptual (this is usually preferred - compresses the image's gamut into the destination gamut).

http://www.cambridgeincolour.com/tut...conversion.htm

Yes, looked OK on the screen, Dave. I tried Perceptual first and then all three other options offered by PI ICCProfileTransformation (Saturation, Relative Colorimetric and Absolute Colorimetric). No luck with any of them. Might go back and have a further play and look more closely at the numbers...

whzzz28 (Nathan) · #30 13-07-2013, 04:08 PM

Looks like your night out there was good one!
Might just be me (or my screen) but the blue hues look interesting, as if washed out a bit.

Sadly I got called up to work, on a Saturday, at 3pm when i was packing the car...

Maybe next time.

RickS (Rick) · #31 13-07-2013, 11:30 PM

Quote:

Originally Posted by whzzz28

Looks like your night out there was good one!
Might just be me (or my screen) but the blue hues look interesting, as if washed out a bit.

Sadly I got called up to work, on a Saturday, at 3pm when i was packing the car...

Maybe next time.

Didn't seem like a good night at the time with clouds coming and going! As usual, I struggled a bit with the colour. It probably could still be improved...

Cheers,
Rick.

Shiraz (Ray) · #32 14-07-2013, 06:34 PM

glorious image Rick. excellent colour and detail.
Be interested in what you find re minor star colour issue.
regards Ray

RickS (Rick) · #33 14-07-2013, 10:06 PM

Thanks, Ray. Will let you know if I find out anything interesting.

TrevorW · #34 15-07-2013, 10:57 AM

Nice !!

jase (Jason) · #35 15-07-2013, 11:42 AM

Rick, are you getting these colours straight out of a colour combine and if so what are your colour weightings you are using? Colours appear rather washed. RGB is an additive colour palette thus as data is stretched, saturation also need to be increased incrementally. My favourite to bring back rich colour is a reasonably heavy stretched DDP RGB layer with ample blurring to curb colour noise, the use this layer as a soft light blend in photoshop. You may need to dial back the opacity a little as it will darken the image somewhat but that's the reason why it needs to be heavily stretched (just watch out for clipping).

RickS (Rick) · #36 15-07-2013, 06:39 PM

Quote:

Originally Posted by TrevorW

Nice !!

Thanks, Trevor.

Quote:

Originally Posted by jase

Rick, are you getting these colours straight out of a colour combine and if so what are your colour weightings you are using? Colours appear rather washed. RGB is an additive colour palette thus as data is stretched, saturation also need to be increased incrementally. My favourite to bring back rich colour is a reasonably heavy stretched DDP RGB layer with ample blurring to curb colour noise, the use this layer as a soft light blend in photoshop. You may need to dial back the opacity a little as it will darken the image somewhat but that's the reason why it needs to be heavily stretched (just watch out for clipping).

Jase: I tried a variety of RGB combinations using eXcalibrator weights (which I liked the best) and PI BackgroundNeutralization + ColorCalibration. I don't have any trouble increasing the saturation in PI but the bluish stars have a tendency to turn a garish cyan colour. I suspect there was something odd going on when I converted to sRGB. I'm going to spend a bit more time playing with the colour data now that we're having some rainy nights

Thanks for the suggestions. I might have a play in Photoshop as well and see what I can do.