How much H alpha?

[ollypenrice]

There is a danger in imaging that one ends up thinking that deeper is always better. I shot 3.5 hours of RGB Elephant Trunk at F7 last night and the result showed the key features. Then I cropped out the same bit of sky from an Ha widefield and added that, very lightly, to red. Sure, I must get some proper Ha at the same FL as the image but, when I do, do I really want the entire thing to turn pink? Or is there a case for a very light kiss of Ha as in this mock up?

Olly

[roundycat]

Narrowband filters only really add detail when that detail is there in the first place. Although it might sound obvious if you spend ages on Ha or O3 and there is only a general splurge of colour as in many of the bigger nebula (and this one) it will not make much difference. If you do RGB on the Veil for instance and then add any of the NB colours there is a big difference to be had.

Sometimes HaGB can be a benefit although you generally have to work on the cyan coloured stars.

Dennis