M42 - Great Orion Nebula
From the author of Sizing Up The Universe
Natural
Tarted Up
03:27 EDT Oct 17, 2004.
Starlight Express SXV-H9 on 4" Tak FSQ refractor at f/5.
Photoshop LayerMask of a long and a short exposure.
Long Exposure:
L = R = Hα = 60 mins, G = 6 mins, B = 4 mins
(unguided 2-minute subexposures).
Short Exposure:
L = R = Hα = 2 mins, G = B = O-III = 2 mins
(unguided 20-second subexposures).