(Click to enlarge)
This is a 2 x 1 mosaic in H-alpha of Auriga using a Canon 100mm lens. It is about 10 x 20 degrees of sky. Dealing with all the stars (> 30000 per frame!) was a big challenge. Also Simeis 147 (spagetti like nebula in lower frame) is very faint so processing it to be visible was tough.