kn27:

"This is Sharpless 2-140 in Cepheus taken with a 115mm apochromatic refractor at f/5.4. It is nearly 11hrs of HaRGB.

For this image I combined the Hydrogen Alpha (Ha) with the RGB channels (70%-R, 15%-G, 15%-B) and then also used the Ha (50%) as Luminance for detail and contrast.”

Sharpless 2-140 by Joel Short