IC 1805: The Heart Nebula in Dynamic SHO

Imaged the Heart Nebula located in the constellation Cassiopeia. This has been a lower priority target for me in the past but got bumped up once I went mono. I'm glad I was able to get a decent shot of it this year. My camera and scope combo give a good FOV on this faint target. Oiii was extremely faint, but luckily good narrowband processing techniques can mask that well.

 

Total exposure time for this image is: 29 hours.

 

Equipment:

- AT65EDQ Scope

- ZWO ASI1600mm-Pro Imaging Camera

- Belt Modded Orion Sirius EQ-G

- QHY miniGuideScope and QHY5L-ii mono guidecam

- Chroma Ha/Oiii/Sii filters

 

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Software:

- N.I.N.A. for capture

- PHD2 for guiding

- PixInsight for Processing

 

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Acquisition:

- 175 x 300" Ha - Chroma 5nm

- 69 x 300" Oiii - Chroma 3nm

- 104 x 300" Sii - Chroma 3nm

- 200 gain and 50 offset, -10C

- 20 flats and flat-darks per filter

- 30 darks from library

- Nights: 10/12, 10/14, 11/6, 11/7/20

 

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Processing:

 

Each Master Image:

- Calibration, Integration, DrizzleIntegration

- DynamicCrop

- DynamicBackgroundExtraction

- Deconvolution (Ha only)

- TGVDenoise + MMT noise reduction using EZDenoise Script

- Arcsinhstretch (x2) to bring to nonlinear

- HistogramTransformation for further stretch

- CurvesTransformation to bring up background level

- StarAlign Oiii and Sii to Ha

- Starnet to remove stars from each master; duplicate starless Ha and set aside to use as Luminance layer

 

Combine Starless Masters via PixelMath:

- Duplicate Oiii and rename to 'f'. CurvesTransformation to boost signal of f and lower background

- R: f*Sii + ~f*Ha

- G: f*(0.7*Ha + 0.3*Sii) + ~f*Oiii

- B: Oiii

- Visit thecoldestnights.com/2020/06/pixinsight-dynamic-narrowban... for more information on Dynamic Narrowband Combinations

- CurvesTransformation to slightly reduce green and boost saturation

 

Starless Ha Luminance Processing:

- CurvesTransformation for contrast

- RangeMask + LocalHistogramEqualization on Melotte 15 to bring back details

- DarkStructureEnhance script at 0.3

- UnsharpMask using a new RangeMask

 

Combine Luminance and Color:

- LRGBCombination with Luminance at 85% weight and chrominance noise reduction enabled

 

Add Back Color Stars and Final Processing:

- StarAlign linear Oiii and Sii masters to linear Ha master

- Arcsinhstretch just barely each linear master

- Duplicate each barely stretched master and Starnet each to remove stars

- PixelMath: Master_Stars - Master_Starless to get just the stars for each channel

- PixelMath: Combine the stars of each channel into a color star image:

- R: Ha_stars

- G: Sii_stars

- B: Oiii_stars

- PixelMath: RGB_Stars + RGB_Nebula to add stars into nebula image

- DynamicCrop to remove edges

- Save and Export

Done