[quote=Peter Ward;365861]Of course, sometimes the bleedin' obvious passes me by.....what colour is
H-Alpha even if you don't have easy access to a solar scope?
Simple!
Just grab a the narrow band H-Alpha filter you are using to image with, and look at a bright white light through it (duh)
Pretty deep red eh?
P.S.
10nm pass filters don't look quite so deep as they obviously pass a little 645nm light...as opposed to 3nm pass versions....they are very crimson.
Hi Peter,
Yes I thought of the same thing. And yes they are quite a deep red.
So that spectrum linked is obviously quite inaccurate. That is a simple and workable test.
Even so the red Photoshop assigns then is not as deep as what you see
through the filter. Suggests that it might be good practice to select a dark crimson colour to Ha layers or channels.
Greg.