Messier 81 Bode's Galaxy and Holmberg IX (Paul Macklin)

Messier 81 Bode's Galaxy and Holmberg IX

Revision title: reprocess

My first major galaxy project with the 8" EdgeHD: Messier 81 (Bode's Galaxy), along with Holmberg IX: an irregular dwarf galaxy that's a satellite to M81 (look above it). If you zoom and explore, you'll see delicate dust lanes in M81, and a good number of tiny (distant) galaxies throughout the image.

This work combines several exposure times, trying to tease out the structure of the core (3 min subs), arms (5 min subs), and outer regions (10 min subs).

Version A: Preliminary image with 24 x 5 min total exposure (and some artistic license in photoshop to bring out the colors).

Version B: Integrating in a range of exposure times:

360 x 5 min
45 x 3 min
45 x 10 min

I integrated all this in AstroPixelProcessor, and saved once with stretch at (15% bg, 3 sigma, 2.5% base) to bring out the outer reaches of the galaxy and faint traces of IFN and Holmburg IX, and once again at (10% bg, 5 sigma, 2.5% base) to bring out more details in the dust lanes. I gave each one minor increases in vibrance, minimal touchup in Topaz (1%/1%/0%/0%), and the combined with 25% opacity on the "dust lane" version.

I also tried to steer away from the tendency to over-clip the blacks. Because APP's star reduction also tried to process the core, I avoided it this time.

Version C: I used AstroPixelProcessor's built-in sharpening at 5%, rather than blending two layers in photoshop. I think this strikes a nice balance.

Version D: Reworked photoshop details.

Version E: Reworked a bit more. D was too green.

Version F: Increased sharpening in AstroPixelProcessor, with a smidgen of star reduction. Use a lighter touch in photoshop.

Version G: Same as F, but decided to not do the AI sharpening. It's growing on me!

Version H: Ultimately added a smidgen of denoising.

B

Title: Increased to 15.75 hours

Description: 360 min @ 5min, 135 min @ 3min, and 360 min @ 10 min. I also tried increasing the dust lanes a bit by blending a less saturated processing of the core at 25% opacity with the overall integrated image.

Uploaded: ...

C

Title: AstroPixelProcessor built-in sharpening

Description: This version uses 5% of APP's built-in sharpening, rather than blending layers in photoshop. I think it came out better.

Uploaded: ...

D

Title: Reworked photoshop edits

Uploaded: ...

E

Title: Fixed colors

Description: The last revision was a little too green.

Uploaded: ...

F

Title: Better processing

Description: Increased the built-in wavelet sharpening in AstroPixelProcessor (5%, 1% protect), used a very tiny amount of star reduction (95%, 95%), and a lighter touch in photoshop. Topaz still minimal at (1/1/0/0)

Uploaded: ...

G

Title: Sans Topaz

Description: A version with no Topaz AI sharpening or denoising.

Uploaded: ...

H

Title: Just a touch of denoising

Description: Ultimately, I liked having a little bit of denoising for when we zoom in on the tiny galaxies. And then clip the blacks a little increase gamma by 5%.

Uploaded: ...

I

Title: reprocess

Description: Just another reprocess. I think the colors are a little better balanced here.

Uploaded: ...

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Status	Advanced success
Started	...
Astrometry.net job	5466107
PixInsight job	K8614D3T92NHAHXF9KRFZ24EKY7RPVOE
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	09h55m33s.922
RA (top/left)	09h57m56s.655
RA (top/right)	09h58m05s.152
RA (bottom/right)	09h53m08s.130
RA (bottom/left)	09h53m05s.511

Dec (center)	+69°04′46″.53
Dec (top/left)	+68°51′20″.13
Dec (top/right)	+69°17′34″.77
Dec (bottom/right)	+69°18′05″.69
Dec (bottom/left)	+68°51′49″.79

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