Hi all

This image was captured on the 30th January 2009 at my local “dark sky” site at the Mangrove Mountain Pony Club. I say “dark sky” in quotes because while it’s darker than my home, it’s not exactly what you’d call a nice dark sky site as it’s still only 20 minutes from Gosford and 1 hour from Sydney so light pollution is still prevalent – especially to the South.

It was my first imaging road trip in 3 months – the first since IISAC2008 and the lack of practise certainly showed. I forgot to take my USA plug to Australia plug 240v power adapter, so I had to power my Canon 350D off batteries. It also took me far too long to drift align and it was past 10pm before I started capturing any photons.

Anyway it’s far from my best image, but here it is – click the image to see the 1200px wide version in the gallery.

The Rosette Nebula (NGC2237)

Continue reading for more information about the capture and processing.

It was a warm night, about 25°C which really increased the noise on my unmodded Canon 350D. I was capturing 5 minute frames with In Camera Noise Reduction (ICNR) turned on at ISO1600 but inspecting the frames as they were downloaded from the camera showed horrible background noise so I reduced it to ISO800.

With the hassle of changing batteries combined with tiredness and generally being unhappy with what was being captured, I called it a night reasonably early and only captured 7 frames at 5 minutes each (2 at ISO1600 and 5 at ISO800). The image was calibrated for flats, aligned and median stacked using Images Plus. Processing involved some DDP stretching in ImagesPlus, followed by further adjustments in Photoshop CS2.

The image was captured with my normal Deep Space Imaging Equipment. 

I was quite surprised with how large the Rosette Nebula was but also how faint it was. I think a modded camera would have really helped to bring out more nebulosity, not to mention the need for darker skies and more exposure. 35 minutes was just not enough and stretching the data really brought out the noise so I had to apply too much noise reduction resulting in a pastelly image with crunchy stars and horrible artefacts.

It’s all a learning experience and it was nice being back out amongst the stars and doing some deep space imaging. Hopefully i’ll get another opportunity to try and do it better soon.

Thanks for looking.

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