Combined normal and H-alpha exposure
Combined: normal light + H-alpha filter NB: Unmodified DSLR!
Canon 5D3 ISO6400 100-400mm L IS lens @ 200mm f/5 8 x 32s = 4.3 minutes
plus ISO25600 7nm H-alpha filter 123 x 32s = 65.6 minutes
This was taken from suburbia. No nebulae are visible in the normal light component but the H-alpha part shows the Pelican Nebula to the right and further hydrogen clouds below.