NGC 7293 - The Helix Nebula imaged with Narrowband Filters
This was my first effort in 100% narrowband, so I played around with various palettes. A palette is the way that the images from the various filters are combined or mapped. Instead of Red:Green:Blue, as in a standard, true color RGB image, we can map the images taken through narrowband filters to these channels in various sequences. The filters that I use are: Hydrogen Alpha (Ha), Oxygen (OIII), and Sulfur (SIII)
For example, the Hubble Palette is SII : Ha : OIII mapped to R : G : B.
The filters are all Astonomik 13nm filters. The subexposures were all 10 minutes, with 160 minutes total for each filter. Scope was a Celestron 80ED at f/7.5, piggybacked on an 8" LX200 classic doing the guiding at f/6.3. Aquired and partial processing in AstroArt4, and finished in Photoshop7. Images were taken over a period of a week from 8/21-8/30/06.
The synthetic green channel was created by combining by Noel's Synthetic Green Astroaction in PhtotoShop.
I think this is the most natural looking.
CFHT Palette
This palette is named after the
Canada France Hawaii Telescope
HST or Hubble Palette
This is the palette generally used for the Hubble Space Telescope images.
Similar to the first image, but with some creative processing in an attempt to approximate the famous Hubble/Mosaic image by Travis Rector.
Link to the Hubble image HERE