Celestial hemisphere:  Northern  ·  Constellation: Cygnus (Cyg)  ·  Contains:  Crescent nebula  ·  IC 4996  ·  NGC 6888  ·  The star 34Cyg
Crescent Nebula, ceteris_paribus
Crescent Nebula
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Crescent Nebula

Crescent Nebula, ceteris_paribus
Crescent Nebula
Powered byPixInsight

Crescent Nebula

Equipment

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Acquisition details

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Description

Crescent Nebula taken with William Optics 71gt with .8x focal reducer/corrector and ASI 1600mm pro.

There are not very many calibration frames as this was a rundown to make sure that my mount problems that appeared over the summer had been successfully worked out. It looks like they have been.

Processed in Pixinsight:

-Calibration and Registration for HA and OIII

HA and OIII separately:

-Minor deconvolution as the stars started looking weird after only a few iterations

-MMT (5 layers). OIII: Did nothing on layer 2 as that had most of the soap bubble and I did not want to risk having MMT disrupt it.

-Masked stretch to background of 0.125 and clipping % = 0

Combined HA and OIII in Pixel Math: Red = HA, Green = OIII, Blue = OIII

Processing on Combined Image:

-A few iterations of Histogram transformation in RGB until Red histogram was stretched much further than Green/Blue. There is a lot more HA than OIII, so this happened quite quickly.

-A few small iterations of Blue and Green separately to bring blue/green up to nearly Red's level, not quite. Did not want to blow out OIII.

-A few very minor iterations of Curves with an S-curve.

Comments

Sky plot

Sky plot

Histogram

Crescent Nebula, ceteris_paribus