NGC 6946 - Fireworks Galaxy

I had set a goal for myself to image and complete processing the fireworks galaxy before independence day this year, and looks like I made it JUST in time! After multiple nights of poor seeing (or poor focus, not really sure) I was finally able to get the last bit of luminance data to complete this image. Happy Independence Day everyone who celebrates it! To the rest of you, hope you enjoy the image nontheless. Constructive criticism of my work is always encouraged!

https://www.reddit.com/r/astrophotography/comments/c8y5gz/ngc_6946_fireworks_galaxy/

Equipment:

* Orion 8in f4.9 1000mm / Flocked / Mask on Turned down edge on primary

* Guiding with ZWO OAG and asi178mm camera

* ASI071mc one-shot-color cam

* ASI183mm pro mono cam

* Hutech IDAS LPS D1 Filter

* Celestron CGEM Mount

The color data was provided by the asi071mc pro camera (0.97"/px) and bayer drizzled with 0.7 drop shrink 94x60s with 071mc pro OSC (~1.5 Hours)

The luminance data was provided by the asi183mm pro camera (0.5"/px) with a D1 light pollution filter 187x120s taken across two nights in late June early July.

Processing steps:

Luminance Data:

* No Drizzle integration of 187x2min 183mm data

* DBE to create L_Orig

* Deconvolution with regularization and no deringing or local support or masks

* Slight MMT sharpening after deconvolution

* TGV and MMT Noise Reduction of L_Orig

* Use Starnet++ to create a star mask, and expand/ convolve it until a mask sufficient for fixing ringing in the deconvolution image can be made. Use clone stamp to paint circles on remaining ringing artifacts not captured by the starmask. This step took multiple iterations to get a balance for de-ringing.

* Replace the ringing stars in deconvolution with L_Orig

* Combine Deconvolution and Noise Reduction image with a clipped / convolved luminance mask (high signal areas are placed with the deconvolution image and low signal areas with the noise reduction... The blurring on the mask creates a subtle transition when combining)

* Stretch with Histogram Transformation

Color Data:

* CFA Drizzle 94x1min OSC data with drop shrink of 0.7 and Local Normalization

* Register with luminance for cropping/alignment

* DBE, Background Neutralization and Photometric Color Calibration

* TGV and MMT Noise Reduction

* HSV Repaired Separation

* Stretch with Histogram Stretch

* Shrink Stars with contours based mask and morphological transformation

Combine L+OSC with LRGB Combination

Adjust curves for contrast and saturation

Create starless version using Starnet++ to boost curves and saturation of main and smaller galaxies in the frame

Recombine starless with stars

Cleanup additional chrominance noise from low color integration time with ACDNR

Shrink medium-size stars using morphological transformation