I'm joining the 'pandemic processing' crowd and finally looking at data from my dome captured scatter-gun style over the last two years or more, where neither time nor energy was focussed on finding and fixing issues. That may be a topic of a more reflective post some other time.
For now, here is 8 hours of the Veil Nebula, captured in July 2018 (how embarrasing is that?). Sometimes my images surprise me and this was one of those times. At 37 south, this doesn't get above 20 degrees so most of this data was captured around 15-20 elevation, with a bit of light dome from Maryborough (pop 10,000 25km away) to boot.
- Takahashi FSQ (which I sold before processing this, oops
, also a long story)
- QHY 367C OSC CMOS camera
Higher res:
https://philhart.smugmug.com/DeepSky...bula/i-b2GTF84
This is true one-shot colour RGB image - there is no narrowband data here which dominates most images of this object. After spending awhile on the background removal, the remaining background variation and colouration (e.g. yellow dusty areas to right of 52 Cygni) I believe are all fairly real. e.g. compare to this image:
clarkvision.com/veil.nebula.200mm. If you know of other deep RGB images of this I'd be interested in the link.
This image has also benefited from the time to download Rogelio's "Mastering PixInsight and the art of astroimage processing" eBook. A few tips from a master PI processor and the time and inspiration that goes with pandemic isolation meant I was able to try additional PixInsight workflow steps (pretty quickly and easily in the end). This image also benefits significantly from the StarNet++ module for PixInsight allowing stars to be reduced and nebula enhanced in separated image layers.
The workflow roughly:
- Calibration, registration, integration with Weighted Batch Preprocessing
- Dynamic Crop
- Automatic Background Extraction (I found optimised ABE parameters more successful than DBE)
- Background Neutralisation & Colour Calibration with default options
- Histogram Transformation
- StarNet module to create separate star mask and nebula images
- Morphological Transformation to reduce star 'presence' (as Rogelio calls it). Some messing around with MT parameters required
- Further Histogram Transformation for nebula layer
- Colour Saturation for both
- PixelMath to add two images back together
- Final Lightroom tweaks for last bit of 'pop'
Second thumbnail attached shows raw image after integration only.
One of my favourite observing memories is hunting out the Veil Nebula in big binos from a dark site (with Aberdeen District Astronomical Society) when I lived in Scotland and I was somewhat addicted to imaging it as well. Never would have expected to do RGB image like this from here.
Phil
- good to see you catching up with these, looking forward to more! 
