M17 with 10" CDK in LRGB and Ha Blend

[John K]

Hi everyone,

Early last week spent 3 nights shooting M17 from near Heathcote, Victoria, Australia under dark skies. There was frost on the scope on one night.

Taken with a 10" CDK scope, AP900 mount and 1600mm camera.

Approximately 4.5 hours of Luminance, with 3.25 hours of RGB data, all 3 minute exposures. The core and surrounding areas also has some Ha blended data I took last year from severally light polluted Melbourne with a 4.5nm Ha filter.

Was hoping to get more of the extended nebulosity, but would say I need to get more Lum hours up on this object to achieve this.

Used Pixinsight and the ArcStretch and HSV Star Repair Script to maintain the core star colours.

High Res version here:
https://photos.app.goo.gl/cc6G6c1M6aznwgeQ7

Clear skies,
John K.

[PKay (Peter)]

Hi John

Not a bad go at the Swan.

With all that data, I reckon you need to have another go at the processing.
Not that I'm an expert, just a gut feeling really.
And heaven knows how many times I was told to 'Repro'.

Maybe it was the 'Star Repair Script' that left all the blue rings, got no idea.
And maybe you clipped the data, once again no idea.

But still, a good result nonetheless

[John K]

Originally Posted by PKay

Hi John

Not a bad go at the Swan.

With all that data, I reckon you need to have another go at the processing.
Not that I'm an expert, just a gut feeling really.
And heaven knows how many times I was told to 'Repro'.

Maybe it was the 'Star Repair Script' that left all the blue rings, got no idea.
And maybe you clipped the data, once again no idea.

But still, a good result nonetheless

No issues at all PKay!

I am very open to constructive feedback - the reason I post is to be able to improve my processing.

Agree - I think that the HSV Star repair may have created some blue halos around esp. the blue stars - I also think the Ha blending I have done without removing the Ha stars has increased this and must admit have not really blended Ha before and need to get an idea on how to best do this.

Clear skies,
John K

[John K]

This is the reprocessed version of HaRGB using Pixel Math in Pixinsight to combine Ha and RGB as described by VisibleDark on YouTube.

10" CDK, AP900 Mount, 1600mm camera.

Approximately 10 hours of Ha (30 minute exposures with a 4.5nm filter) and 1.5 hours in Blue, and 45 minutes in Red, 1 hour in Green (13 hours, 15 minutes total exposure).

High Res Version;

https://photos.app.goo.gl/EUyFbudmsuxMdZyc6

Clear Skies,
John K.

[PKay (Peter)]

Much better John.

Lots more detail and contrast (all the 'wispy bits' have appeared) and the stars have improved heaps.

Good job