Eastern Veil. New processing methods compared to old

[timh]

It is difficult to get decent broadband images from my location as light pollution gets ever worse and this - combined with haziness – makes it often difficult to make out even 3 rd magnitude stars.

But - aside from goingg narrow band - modern processing tools do help and have improved immensely and – looking back – the way I process a deepsky image now is very different from the state of the art 5 or 6 years ago. So I thought that it might be interesting to take the same set of data and compare the resulting images after processing using either 2019/ 2020 or current methods to get a measure of how much has changed.

The image here is of the East veil nebula covering only a tiny fraction of the entire nebula that StarzSkies has nicely captured below.

Skywatcher S 200 Newtonian, Baader MkIII coma corrector F 5.0, Baader type II UV/IR filter, Ioptron CEM 70G mount , PHD2 guided using a f = 400mm 80 mm Achromat and ZWO ASI 120 MM camera. The imaging camera was a ZWO ASI 1296 MC cooled to -10C.

Capture in Sharpcap 4.1 was 219 x 40s frames at unity gain, dithered and pre-processed in PixInsight 1.9 to produce a CFA 1x drizzle integration.


The tools used in the 2020 processing route in PIxInsight were --

DBE (Smoothing and minimising the light pollution background)
CROP (Eliminating the image edges that couldn’t be adequately reduced)
PCC (Photometric colour calibration)
STARMASK, MORPH (Reduce the size of stars)
HISTOGRAM TRANSFORMATION (Stretch the image)
CURVES (Adjust stretch, background and colour)
MSN (Multiscale noise reduction)


The tools used in the 2026 processing route in PIxInsight were --

MSG (multiscale background gradient reduction based on MARS data)
DBE (Smoothing and minimising residual light pollution background around the edges )
CROP (Eliminating the image edges that couldn’t be adequately reduced)
SPCC (Spectrophotometric colour calibration)
RC_BlurExterminator( Star size reduction, Slight sharpening of nebula details)
RC_StarExterminator (Create separate starless and star images)
MAS (Multiscale Adaptive Stretch – retains colour saturation during stretch)
EXP, ARCSINh, CURVES (Tools to adjust the stretch v background) – to starless image
CURVES (applied to star image)
PIXMATH (recombine the starless and star images)
RC NoiseExterminator( AI-based noise reduction of luminance and colour noise)

The two alternatively processed images are shown below along with a side by side close up of the central region.

[Howardk]

Very interesting
Thanks for posting this

We have advanced these past 6 years in post processing

[turfpit]

Tim

Interesting and worth doing. It just shows how productive these periods of poor weather can be. I did a similar exercise with my 2020 lunar data - same data, improved software, better outcome. I do wonder what part improved processing skills plays in this?

Dave