Flaming Star Nebula POSS2 data

[gorann]

This is an RGB image made from POSS2 red and blue filter data with a synthetic green channel (a 50:50 mix of red and blue). I added a bit extra luminosity to the "blue dragon" by mixing in some blue data as a luminosity layer. All in PS CS5.

POSS2 is a 1990ies sky survey based on monochrome glass plate images (red or blue filtered) taken with a 1.2-m Schmidt camera at the Mt. Palomar Observatory. Data is available free and working with it is both fun and a good therapy while waiting for clear skies:
http://archive.stsci.edu/cgi-bin/dss_form

Comments and suggestions always welcome of course

[Daniel-K]

i really like, a little bit of a gradient across the image.  i like the way the star is illuminating the nebula.

[gorann]

10 minutes ago, Daniel-K said:

i really like, a little bit of a gradient across the image.  i like the way the star is illuminating the nebula.

Thanks Danny!

Yes, I also like that star shine a lot. I wondered myself if that is a gradient or not. I will try to look into it. Maybe someone can say for sure? I can of course let it go through a round of GratientXtermnator to see what i does to it.

[Daniel-K]

1 minute ago, gorann said:

Thanks Danny!

Yes, I also like that star shine a lot. I wondered myself if that is a gradient or not. I will try to look into it. Maybe someone can say for sure? I can of course let it go through a round of GratientXtermnator to see what i does to it.

have you tried HLGV? theres a fair bit of green in the bottom.  i think that could balance it out a little more then just try aligning the RGB in PS. 

[gorann]

19 minutes ago, Daniel-K said:

have you tried HLGV? theres a fair bit of green in the bottom.  i think that could balance it out a little more then just try aligning the RGB in PS. 

I actually have difficulties seeing the green you mention on my monitor. When I use the Eyesdropper in Photoshop it reads 22:22:22 for RGB at the bottom. I have my Photoshop on a Mac and Bernal has sadly not made a Mac version of HLGV.

[Daniel-K]

5 minutes ago, gorann said:

I actually have difficulties seeing the green you mention on my monitor. When I use the Eyesdropper in Photoshop it reads 22:22:22 for RGB at the bottom. I have my Photoshop on a Mac and Bernal has sadly not made a Mac version of HLGV.

ah its in the lower left corner

[gorann]

39 minutes ago, Daniel-K said:

ah its in the lower left corner

Sorry, but the Eyesdropper cannot find any green there either.

[Daniel-K]

i ran it through HLGV, deffo there. not much. if you cant see it i wouldnt worry

[gorann]

 Ok. Could it be your monitor?

[alacant]

Hi. That's interesting. Thanks for posting. I had a go at the colour.

[gorann]

 

17 minutes ago, alacant said:

Hi. That's interesting. Thanks for posting. I had a go at the colour.

When I look at your image, I also see green in the left corner but it seems to include my signature (which is pure white). Maybe something happened in the SGL system during my posting. I post it again here:

[alacant]

Hi. Dunno. I see blue/magenta. I adjusted the curves to reduce it. I did not mask your signature. HTH.

[rodrigol]

Awesome! And a lot of useful information getting exchanged here as well :-) Thanks!

 

[gorann]

18 minutes ago, rodrigol said:

Awesome! And a lot of useful information getting exchanged here as well :-) Thanks!

 

Thank you Rodrigo!

I spent most of this Sunday working on this data and now when I now look at the image again, after dinner and a movie, I have to say that I really like it , especially the detail in the blue "dragon" and how it appears to cast shadows on the red nebulosity below and how the central star lights up the surroundings, as Danny pointed out.

I just googled for IC405 images. Since it is not my data, and I am just the interpreter, I take the liberty to say that it is difficult to find any better renditions of this nebula than this one, captured 20+ years ago on glass plates. It is just amazing how today's digital technology allows us to stretch the signal and help bringing it out.

[gorann]

On 2017-02-19 at 17:22, Daniel-K said:

i really like, a little bit of a gradient across the image.  i like the way the star is illuminating the nebula.

 

20 hours ago, alacant said:

Hi. Dunno. I see blue/magenta. I adjusted the curves to reduce it. I did not mask your signature. HTH.

I now figured out that the blue shine in the top left corner is not a gradient but caused by two big blue stars just outside the frame. Here is what the blue filtered image looks like on POSS2 if I shift the image center in that direction. In general I think the POSS2 data is virtually free from gradients.

[Daniel-K]

On 2/19/2017 at 18:25, gorann said:

 Ok. Could it be your monitor?

Doubt it bud, i use my setup for landscape photography so its top class 

[gorann]

1 hour ago, Daniel-K said:

Doubt it bud, i use my setup for landscape photography so its top class 

Well, then it is a puzzle. PS shows RGB 21:21:21 all along the bottom and I still do not see it on my screen. Maybe it is SGL. Have a look at my post on Astrobin:

http://www.astrobin.com/284243/B/