NGC6823 Emission nebula and star cluster. Narrowband Image with HSHO filters as LRBG (see below for explanation).



Boren Simon 8" Powernewt with ASA f/2.8 2KORRR reducer/corrector

SBIG ST-8300M CCD camera with FW8-8300 Filter Wheel (LRGBHOS)

Orion Mini Autoguider Guide Scope w/Fishcamp Starfish guide camera

Atlas EQ-G


Technical Details:

This is an image produced by a monochrome camera, using filters to image the red, green, and blue colors separately, and then they are combined in software to generate a color image. In this case, special "narrowband" filters were used (instead of simple red, green and blue) that take small slices of the visible light spectrum. Each of the filters reveals the presence of certain chemical elements in the stars, nebula, and gases in space. Sulfur, Hydrogen, and Oxygen (SHO) are represented here as red, green and blue, and combined into a full color image. For example, the blue areas of the nebula are rich in oxygen. So, when done like this, the pretty pictures can actually help map out which chemical elements make up the nebula!


705 mins total exposure (11.75 hrs)

Luminance: Hydrogen: 73x300s

Red: Sulfur-II: 32x300s

Green: Hydrogen-alpha: 73x300s

Blue: Oxygen-III: 36x300s

  • Steven Meyer-Rassow 3y

    No idea what any of the technical details mean, but the final image is absolutely stunning!
  • Sai Achanta 3y

  • lacomj 3y

    Steven Meyer-Rassow Good point!! I added a basic explanation of process that may help a bit (still may be a bit technical).
  • Ricardo 3y

    Wow Fantástic!
  • Ian Crichton 3y

    Really good image, excellent detail
  • Terry Hancock 3y

    Jeff, apologies mate......I have no idea how I missed this. Great image
  • Craig B 9mo

    your description of the equipment used and processes taken, is very informative and, frankly, slightly above my comprehension levels. Great shot too! Should be for almost a 12 hour exposure ;-)
  • Benjamin O. Sayag 9mo

    Very impressive
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Taken on July 22, 2012
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