B33 . This new image of the Horsehead nebula reveals more of its dynamic range in the colour data than the prevous images so far. I was using my ten inch F4.8 reflector, PHD auto guiding and an Atik 383L mono CCD camera. By capturing five minute sub frames, dark frames and flat field frames I reduced the effect of vignetting in the colour data in the final image. The total exposure times were 30 minutes in red, 30 minutes in green, 40 minutes in blue and 60 minutes in H Alpha.
