Packman Nebula NGC 281

Date of image 29/07/2016

The Packman nebula NGC 281. Processed using DSS. 

Hardware details: Camera: Canon 600D (astro modded). Telescope: SW Evostar 120 with Baader UHC-S filter. Mount: AZ-EQ6 guided using a ST80 synguider. Image details: Lights: ~40 x 3min at ISO 800, Darks: 50 x 3min 0 sec at ISO 800 (from dark library), Lights and darks separated by 30 sec intervals. Flats: 50 x 1/50s at ISO 800, Bias: 50 x 1/4000 at ISO 100.

I have been trying to capture this nebula for a while now because Cassiopeia is really well placed for a full nights imaging.

Atmospheric transparency was excellent, no clouds after 00:00. Auto guiding was reasonably stable, but there was quite a lot of corrections in the RA axis, I used some east heavy balancing and reduced the RA aggressiveness of the auto guider.

I increased the saturation by 30% and manually aligned the colour channel histograms. I stretched the red, green and blue channels by about the same amount to try and show the subtle difference in colour. I have noticed some darkening round the edges of the image that could be vignetting or a result of the smaller stack size in these regions. What ever it is, it was not corrected by the flats.

I actually like the subtle tones in colour throughout the nebula - I didn't think I caught this detail looking at the individual frames. I didn't want the H alpha red to overpower the other emissions so I stretched the colours accordingly.