Equipment:
ZWO ASI 1600 MM Pro @ -20°C
+ C14 & Starizona Hyperstar @ 675 mm (f/1.9)
+ Baader 2" LRGB filters
+ Celestron EF
+ Tempest Cooler
+ Omegon Dew Heater
+ Astrozap Dew Shield for C 14 Hyperstar
on CGE-Pro mount
Cable managment to mitigate Hyperstar diffraction spikes.
Autoguiding:
Artesky 70 mm Guidscope (f=400 mm)
ZWO ASI 120 MM mini
PhD2 (Multistarguiding)
Dither every 5 subs
light frames:
780 x 30 s (luminance, gain=75, offset=15)
472 x 30 s (red, gain=75, offset=15)
477 x 30 s (green, gain=75, offset=15)
566 x 30 s (blue, gain=75, offset=15)
dark frames:
60 x 30 s
flat field frames (sky flats):
125 x 1 s /channel
acquired with N.I.N.A.
average FWHM: 2.1" - 2.4"
Remaining Issues- more L data is required to improve s/n ratio
Post-ProcessingPixInsightLRGB channel (linear stage)
star alignment, rejection of bad frames using subframe selector & blink, NSG script, image Integration, dynamic crop, dynamic background extraction
RGB processing (linear stage)
linear fit of R & G channels wrt B channel, RGB channel combination, photometric color calibration, EZ Soft Stretch
L processing (linear stage)
EZ Soft Stretch
LRGB processing (non-linear stage)
LRGB combination with chrominance noise reduction, color saturation enhancement using curves transformations, SCNR (average neutral, amount = 1.0), remove stars with StarNet2, create luminance mask, invert luminance mask to protect brighter parts of the nebula, remove luminance mask, increase color saturation of contrast enhancements with histogram & curves transformations
Topaz Denoise AIRemove short-wavelength noise from starless image:
Low Light Mode On
Sharpen: 0
Remove Noise: 5
PixInsightFinally, add stars to starless image using Pixelmath, final contrast/color saturation enhancements with curves transformations and color corrections with histogram transformations.
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