This is my second attempt to create a narrow band astrophotography image. This technique uses a monochrome camera and special filters that block all but very narrow segments of the spectrum containing the emissions from ionized gasses (hydrogen, oxygen, and sulfur). The filters block nearly all the light pollution so I can capture images in my back yard and not have to travel several hours to find dark skies. The trade off is it's difficult to create natural looking images. Each filter is associated with Red, Green, or Blue which are the colors normally mixed to create a normal photograph. There are several "recipies" for this but I've chosen maybe the most common, often used for Hubble images.
The Elephant's Trunk Nebula - IC1396 in Narrow Band
IC1396 is located in the constellation Cepheus ~2400 light years from Earth. This image was captured from my back yard (7 on Bortle light pollution scale) with narrow band Sulfur, Hydrogen Alpha, and Oxygen filters. It's processed in the classic Hubble Palette (Sulfur assigned to Red, Hydrogen Alpha to Green, and Oxygen to Blue).
Click on the image for a much larger view.
An even more nerdish post with equipment and acquisition info is available here:
https://www.astrobin.com/xtgomu/?nc=user
