Hubble-Inspired Messier 1 Crab Nebula - 4 color narrowband (Paul Macklin)

Hubble-Inspired Messier 1 Crab Nebula - 4 color narrowband

Revision title: More natural background processing

Long before getting into astrophotography, I've been awed by Hubble's class image of Messier 1 in its reds, golds and emerald green.

While I don't have the same filters and wavelengths available, newer consumer ALP-T Ha/[OIII] and [SII]/Hb filters open up new possibilities to see what features are strongest in each channel and try to recreate the overall look:

The outermost details are most visible in Hydrogen-alpha.
Oxygen-III strongly correlates with Hydrogen-alpha
The strong filaments are prominent in Sulfur-II
Hydrogen-beta (not typically imaged!) is the only channel that strongly emphasizes the soft "core"

Based on matching this to the iconic NASA image, I went with an Ha-S-O-Hb palette:

Ha (red-orange): x1.25

(100,25,1)

[SII] (gold): x2.5

(100,100,1)

[OIII] (blue-green): x1

(1,50,100)

Hb (teal): x6

(1,100,100)

Deconvolution with BlurXT brought out a lot of the finer filament structure. I was really pleasantly surprised how close we can get to these iconic images with the newer narrowband options available.

I just added a separate post with intermediate processing steps here: https://www.astrobin.com/popx3s

It's worth mentioning that these were imaged on an 8" EdgeHD running without its 0.7x reducer. It plate solves out to about 2100mm, very close to the expected value of 2125mm (f/10.456). Because I'm imaging in narrowband and at a relatively slow f/10.456, I decided to use 10 minute exposures.

Prints available at: https://mathcancer.darkroom.com/products/nebulas/1292080

B

Title: Hydrogen-alpha

Description: This is my raw Hydrogen-alpha stack in my palette, setting all other channels to x0 in AstroPixelProcessor.

Uploaded: ...

C

Title: Sulfur-II

Description: This is my raw Sulfur-II stack in my palette, setting all other channels to x0 in AstroPixelProcessor.

Uploaded: ...

D

Title: Oxygen-III

Description: This is my raw Oxygen-III stack in my palette, setting all other channels to x0 in AstroPixelProcessor.

Uploaded: ...

E

Title: Hydrogen-beta

Description: This is my raw Hydrogen-beta stack in my palette, setting all other channels to x0 in AstroPixelProcessor.

Uploaded: ...

F

Title: Slightly improved background handling

Uploaded: ...

G

Title: More natural background processing

Description: I went back to an earlier version with more natural background processing.

Uploaded: ...

Antlia ALP-T 5nm Dual Narrowband Filter

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Status	Advanced success
Started	...
Astrometry.net job	8954738
PixInsight job	RBGA2V6W6X2AHVO3QV6IG68SXOHL7KHX
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	05h34m33s.451
RA (top/left)	05h35m13s.474
RA (top/right)	05h33m53s.787
RA (bottom/right)	05h33m53s.535
RA (bottom/left)	05h35m13s.870

Dec (center)	+22°01′06″.94
Dec (top/left)	+22°10′18″.50
Dec (top/right)	+22°10′22″.43
Dec (bottom/right)	+21°51′55″.58
Dec (bottom/left)	+21°51′50″.94

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