Celestial hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  Iris Nebula  ·  NGC 7023
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A Dusty Iris, Scott Denning
A Dusty Iris
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A Dusty Iris

Getting plate-solving status, please wait...
A Dusty Iris, Scott Denning
A Dusty Iris
Powered byPixInsight

A Dusty Iris

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Description

2020 08 17 Iris and Dust from the medicine Bow Mountains of Wyoming

Iris Nebula in Cepheus imaged over 3 nights Aug 14-16 (new moon) from the cabin

C8 EdgeHD Hyperstar FL=400 w ZWO ASI294MC Pro on Paramount MyT (unguided)

Total of 515x60s subs (T=-15C, gain=130, offset=30) mostly from the night of Aug 15

Calibration frames: 30x60s dark; 30x2s flat; 30x2s flat-dark

Processed in PixInsight 1.8.8-5 Aug 18

Calibrated, cosmetic corrected, debayered, subframe selected & wtd for median, FWHM, ecc, SNR

Integrated best 364 frames (6 hours exposure at f/2!)

Photometric color correction

Automatic Background Extraction

Light histogram stretch to nonlinear

Nonlinear processing followed Old Wexi tutorial :

https://www.dropbox.com/s/dw6imbwpq8brvdt/Howto_enhance_nebuala_without_pushing_stars.wmv?dl=0

Clone nonlinear image to "original" and "starless"

Process "starlesss" clone:

REDUCE SMALL STARS:

StarMask scale=7, growth=3, small=1, comp=2 smooth=8 & apply

Mukltiscale Median Transform layers=6 diasble 1-4 (up to 8 pixels scale) apply TWICE (just to stars)

REDUCE MEDIUM STARS

Morphological Transformation Erosion apply twice (just to stars)

Remove star mask

REDUCE LARGE STARS

Use Range Selection (lower limit) to isolate biggest stars but not nebulosity

Iterate three or more times, making them big and smooth

Apply to starless image

Use HDR Multiscale Transform (5 layers) on big stars only (multiple iterations?)

EXPONENTIAL TRANSFORMATION OF STARLESS IMAGE IN PIXELMATH

With big stars masked off

RGB/K = 1-(1-$T)*(1-$T) to everything but big stars

COMBINE STARLESS & ORIGINAL IMAGES IN PIXELMATH

F=0.4 (or whatever)

RGB/K = (1-(1-$T)*(1-s)*F) + ($T * ~F)

Apply to original

Repeat as needed with smaller F (e.g., F=0.2)

Tweak histogram between each exponential stretch to eliminate left shoulder (don't clip shadows at all)

Final histogram and curves tweaks



=======================

Dusty dirty universe!

Space is just chock full of dirt. Some might say "ewww" but hold on -- don't clean it up -- it's important.

This is an actual photo of a huge expanse of dust in the constellation Cepheus (the King of Ethiopia) taken over the weekend from our cabin in Wyoming. It's more than 6 hours of exposure over three crystal clear nights at 10,500 feet elevation at the dark of the Moon.

Everything in the universe that's not hydrogen or helium gas is made from dust. Every grain of sand. Every crystal of rock. Every blade of grass. Every flower, every feather, every drop of water and flake of snow.

Everyone you love and everyone you don't.

It's made inside of stars and it's left in great clots and clods along the plane of the galaxy as the spiral arms churn through the gas with their waves of creation and destruction.

The dirt is cold and brown and sooty and greasy. It's full of carbon and oxygen, nitrogen and sulfur. The deep cold lets gas coalesce around it and self-gravitate into new stars.

Swirling space dirt is left behind when new stars blow the gas away, and scrunches down to melt and meld and separate into planets and plants and people.

Huzzah for the filthy fecund universe that brings forth such glory!

Comments

Revisions

  • A Dusty Iris, Scott Denning
    Original
  • Final
    A Dusty Iris, Scott Denning
    B

B

Description: 2020 08 17 Iris Dust from the cabin

Iris Nebula in Cepheus imaged over 3 nights Aug 14-16 (new moon) from the cabin

C8 EdgeHD Hyperstar FL=400 w ZWO ASI294MC Pro on Paramount MyT (unguided)

Total of 515x60s subs (T=-15C, gain=130, offset=30) mostly from the night of Aug 15

Calibration frames: 30x60s dark; 30x2s flat; 30x2s flat-dark

Processed in PixInsight 1.8.8-5 Aug 18

Calibrated, cosmetic corrected, debayered, subframe selected & wtd for median, FWHM, ecc, SNR

Integrated best 364 frames (6 hours exposure at f/2!)

Photometric color correction
Automatic Background Extraction

Light histogram stretch to nonlinear

Nonlinear processing followed Old Wexi tutorial :
https://www.dropbox.com/s/dw6imbwpq8brvdt/Howto_enhance_nebuala_without_pushing_stars.wmv?dl=0


Clone nonlinear image to "original" and "starless"

Process "starlesss" clone:

REDUCE SMALL STARS:
StarMask scale=7, growth=3, small=1, comp=2 smooth=8 & apply
Mukltiscale Median Transform layers=6 diasble 1-4 (up to 8 pixels scale) apply TWICE (just to stars)

REDUCE MEDIUM STARS
Morphological Transformation Erosion apply twice (just to stars)
Remove star mask

REDUCE LARGE STARS
Use Range Selection (lower limit) to isolate biggest stars but not nebulosity
Iterate three or more times, making them big and smooth
Apply to starless image
Use HDR Multiscale Transform (5 layers) on big stars only (multiple iterations?)

EXPONENTIAL TRANSFORMATION OF STARLESS IMAGE IN PIXELMATH

With big stars masked off
RGB/K = 1-(1-$T)*(1-$T) to everything but big stars

COMBINE STARLESS & ORIGINAL IMAGES IN PIXELMATH

F=0.4 (or whatever)
RGB/K = (1-(1-$T)*(1-s)*F) + ($T * ~F)
Apply to original

Repeat as needed with smaller F (e.g., F=0.2)

Tweak histogram between each exponential stretch to eliminate left shoulder (don't clip shadows at all)

Final histogram and curves tweaks


=======================

Dusty dirty universe!

Space is just chock full of dirt. Some might say "ewww" but hold on -- don't clean it up -- it's important.

This is an actual photo of a huge expanse of dust in the constellation Cepheus (the King of Ethiopia) taken over the weekend from our cabin in Wyoming. It's more than 6 hours of exposure over three crystal clear nights at 10,500 feet elevation at the dark of the Moon.

Everything in the universe that's not hydrogen or helium gas is made from dust. Every grain of sand. Every crystal of rock. Every blade of grass. Every flower, every feather, every drop of water and flake of snow.

Everyone you love and everyone you don't.

It's made inside of stars and it's left in great clots and clods along the plane of the galaxy as the spiral arms churn through the gas with their waves of creation and destruction.

The dirt is cold and brown and sooty and greasy. It's full of carbon and oxygen, nitrogen and sulfur. The deep cold lets gas coalesce around it and self-gravitate into new stars.

Swirling space dirt is left behind when new stars blow the gas away, and scrunches down to melt and meld and separate into planets and plants and people.

Huzzah for the filthy fecund universe that brings forth such glory!

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A Dusty Iris, Scott Denning