B33

These images of the Horsehead nebula were taken on five seperate evenings. The exposure times were 9 hours using an Astronomik H-alpha filter, 2 hours using an Olll filter, 2 hours using a Sll filter and
two, 30 minute exposures using green and blue filters. I captured ten-minute sub frames with matching dark frames and combined them with flat-field frames to reduce the effect of vignetting in the final image. The telescope I was using was an 80mm f/7 refractor with a focal reducer and field flattener making f/6.3. I was using an Atik 383L mono CCD camera, PHD auto guiding and a Vixen Atlux mount. I consider this part of the night sky very challenging from inner city light pollution . Notice that I have managed to reveal clouds of nebulosity in the fainter regions. The total exposure time was 14
hours.

RGB colour

Hubble Palette

RGB colour narrowband luminance

Narrowband luminance with narrowband RGB colour