M20 First LRGB with 7e

This is my first real attempt to do an LRGB with an ST7e NABG. I think I need to expose the blue longer. Does this look like a good focues. Used FS78. Just outside of Eugene, Or

Sam

Attached Image:

You do have some of the blue nebulosity present, but it's weak. If you are imaging from as far north as Eugene, you have significant blue extinction from the atmosphere - this object is low enough to need a significant boost to the blue exposure. I would go at least 150% of the recommended blue exposure (1:1:1.6 would become 1:1.4:2.5, for example, including a boost to the green as well).

Ron Wodaski
author of "The New CCD Astronomy"
http://www.newastro.com