My best Gabriela before these tests with Halfa:
http://astronomia-e-astrofotos.10697..._k5_130509.jpg
http://www.astrobin.com/full/41885/0/
GSO 305 mm - Canon Rebel XT - ISO 800 - 40 m - 20 x 2 m - OAG - DSI1- Coma Cor.
I always say: the secret of one astrophoto is the seeing of the sky.
Perhaps I will use de Halfa as help to red channel. Not as Halfa. Only a little bit of red information, free from light pollution.
At this moment, I am only testing and exploring the possibilities and how to process the files.