The squid nebula is a faint emission nebula, lying optically within the larger Ha region of SH2-129. It was only discovered in 2011 by Nicolas Outters, an amateur astronomer. It has a large apparent size but is very, very faint. Recent studies show that OU4 might really lie within SH2-129. I only learned about this nebula when I started astrophotography and it was one of the targets that drew me to the hobby. I am happy that I managed to capture it, even though it proved to be quite a journey.

The squid is really, really faint. I fought rain and storm, light pollution, moon and clouds, light pollution, reflections and misconfigurations, light pollution, electricity outages and equipment failure. Did I mention light pollution? Oh, and I had two clear nights all last month. I used Voyager automation to just continue to gather data during cloud holes and sorted out the mess afterwards. Fortunately no rain on those 10 nights I gathered data, so that worked out. From 1020 images, 261 remained. Around new moon I shot only O3. When the moon was fuller, I shot only Ha, the other nights I used 1 Ha for every 5 O3.

After that easy part, processing the data proved to be a real challenge. It needed the following steps:

Calibration with Pixinsight "by hand"

Neither PI WBPP nor APP worked well. I do not know why. Calibrating manually worked better, but there remained an uncorrectable circle/rectangle in the integration of the O3. I assume it might be a reflection between camera and filter. This artefact limited the amount of stretching I could do to the O3 data.

Local Normalization (no luck using Adaptive Normalization)

Image Integration

Noise Reduction: Mure Denise

ABE

DBE

Deconvolution

StarNet

On O3 Nebula: Noise Reduction: MMT

Masked Stretch

ArcSinHStretch

DBE

ChannelCombination

BackgroundNormalization

MMT Noise Reduction (Chrominance)

On Ha: HDRMultiscaleTransform

MLT sharpening

Curves Transformation

I still feel there is potential to optimise the look of the stars. Also, it can use more data still. I will return to this target, but for now turn to easier things.