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Post by Deleted on Nov 26, 2017 6:38:36 GMT
Camera - GStar Ex3 178 2x2 RGB Telescope - 200/1000 Newt Mount - HEQ5 Focal Reducer/Barlow - NA Filters - NA Exposure length - 20s Stacks - 0 Software - Altair Capture Settings - Gain 5, Gamma ~0.55 Any Processing (on-the-fly, post-processing) - Auto Dark Subtraction Conditions - 20% moon, bit hazy General Location (Town or area & State & Country) - Esk, Queensland, Australia
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Post by Dragon Man on Nov 26, 2017 8:30:28 GMT
Beautiful Tarantula Robert Good to see you left it Aqua, not changed it to pink like many astrophotographers do They get so used to seeing pink nebulas, and then all of a sudden they see Tarantula in Aqua and think their colour settings are wrong and make it pink. WRONG!
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elpajare
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home town/country: Girona-Spain
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Post by elpajare on Nov 26, 2017 15:47:08 GMT
Omegon 154/1370+ Infinity + 0,5 red Infinity software ( NO Gain control) NEQ5 Goto 20x30" Adjusted Levels/Contrast/Hue saturation with GIMP Nice object Robert. Its a pity we can not see in the Northern Hemisphere.
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Post by howie1 on Nov 27, 2017 1:13:00 GMT
Good article on nebula colors in the link below ... weird site though ... when you open the link below you'll see a bunch of hyperlinks but do not click on the links. The actual article is underneath all those hyperlinks, so dont click the hyperlilnks but just scroll down, and down, and down (!) to read the article which is actually underneath all those hyperlinks. Clark doesn't like modded cameras as you will see mentioned in the webpage! LOL www.clarkvision.com/articles/color.of.nebulae.and.interstellar.dust/
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Post by Dragon Man on Nov 27, 2017 3:19:49 GMT
Excellent article Howie. Thanks
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Post by Deleted on Nov 27, 2017 6:26:15 GMT
Beautiful Tarantula Robert Good to see you left it Aqua, not changed it to pink like many astrophotographers do They get so used to seeing pink nebulas, and then all of a sudden they see Tarantula in Aqua and think their colour settings are wrong and make it pink. WRONG! Thanks Ken. That colour seemed to be about right. I guess it's a combination of red emission and blue relection nebulosity
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elpajare
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Post by elpajare on Nov 27, 2017 8:22:53 GMT
Fantastic article, Howie.
Thanks
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Post by davy on Nov 27, 2017 10:17:49 GMT
Great image,,, great read on the article Howie
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elpajare
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home town/country: Girona-Spain
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Post by elpajare on Nov 27, 2017 10:34:41 GMT
This article gives some interesting ideas to get real colors.
If we start from a spectroscopic analysis of the object (Star Analyzer 100) we could identify the most interesting lines of the object as the different types of emission of H I and O I-II-II to know the real colors that our photographs should have.
This is a new field of research very interesting
To start:
Hydrogen-Alpha (656.3 nm, 0.6563 micron), red, 3 to 4 times the intensity of H-beta. Hydrogen-Beta (486.1 nm, 0.4861 micron), blue-cyan. Hydrogen-gamma (434.1 nm, 0.4341 micron), blue-violet, weaker than H-beta by about half. Oxygen III (500.7 nm, 0.5007 micron) blue-green. Oxygen III (495.9 nm, 0.4959 micron) blue-green, ~5x weaker than 500.7 nm line. Nitrogen II (658.3 nm, 0.6583 micron) red. Nitrogen II (654.8 nm, 0.6548 micron) red, about 1/4 the 658.3 nm line. Helium I (587.6 nm, 0.5876 micron) orange. Helium II (468.6 nm, 0.4686 micron) blue.
To continĂșe:
Red, pink = H-alpha where dust is absorbing H-beta and H-gamma in hydrogen emission nebulae Magenta, light blue = H-alpha + H-beta + H-gamma in hydrogen emission nebulae with moderate absorption by dust Pink = H-alpha + H-beta + H-gamma + Oxygen and/or Sulfur (OIII / SII) Orange, brown = dust Light sky blue = Rayleigh scattering from particles a little smaller than visible light Deep sky blue = Rayleigh scattering from particles a much smaller than visible light Green (teal) and bluish-white = Oxygen (OIII) dominated
To finish
A hard work with GIMP or Photoshop to match frequencies and colors...
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Post by Deleted on Nov 30, 2017 8:41:58 GMT
"Omegon 154/1370+ Infinity + 0,5 red"
You used an RC scope for this image?
How useful is it for video?
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elpajare
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home town/country: Girona-Spain
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Post by elpajare on Dec 1, 2017 8:28:25 GMT
Yes, i have used a RC with the Infinity. I need almost 30" to see something in the screen.
Pros: Nice and sharp stars without aberrations. Light weight and compact. No aberrations.
Contras: Reduced opening and lack of light. Central obstruction its a handicap. Increase of exposure.
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