Crescent Nebula (reprocessed)

[JohnH]

This is data I took in October of last year on the 10th and 17th. I have run it through updated and new imaging software. In reality, the new software probably means that processing is easier even if it is not always better.



I have consciously attempted to reduce the impact of the stars which are dense in this region.

The details are:-

Capture:
Sharpstar 15028 HNT (150mm diameter f2.
ZWO ASI 1600MM Pro at -15C
ZWO ASIAir (Camera control, Guiding, Plate Solving etc)
iOptron CEM25P

Subframes:
L - 76 x 15 secs (19 mins)
R - 30 x 40 secs (20 mins)
G - 30 x 40 secs (20 mins)
B - 30 x 40 secs (20 mins
Ha - 28 x 210 secs (98 mins)
Total - 2 hrs 47 mins

Processing Stages:

Pixinsight:
WBPP for
Calibration
Cosmetic Correction
Measurements
Bad Frame Rejection
Reference Frame Selection
Plate Solving Reference Frame
Registration
Local Normalisation
Integration
Autocrop
(Running time 1 hr 42 mins)

PixelMath - L + H = New Luminance (New_L)
New_L PSFImage for FWMH (PSF dia = 2.3px)
New_L BlurXTerminator

GraXpert:
New_L

Pixinsight:
New_L NoiseXTerminator
RGB_ChannelCombination
SpectrophotometricColourCalibration
NRGBCombination

GraXpert:
NRGB

Pixinsight:
NoiseXTerminator_HaRGB
LHaRGBCombination
StarXterminator
CloneStamp (remove residual stars)
(Nebula) GeneralisedHyperbolicStretch
CurvesTransform (create a Nebula Mask)
(Stars) GeneralisedHyperbolicStretch

Affinity Photo 2 (as Tiff):
Adjust saturation/vibrance
Hi-Pass Filter
Combine Nebula and Stars

This was my previous version:



Regards,

John

[Carole]

The original was pretty good John, but I think the new process shows up the Ha Data much better with better colour.

Always worth going back and reprocessing data as your skills develop.

Carole