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Markarian's Chain, Michał Kostrzewa
Markarian's Chain, Michał Kostrzewa

Markarian's Chain

Markarian's Chain, Michał Kostrzewa
Markarian's Chain, Michał Kostrzewa

Markarian's Chain

Equipment

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Acquisition details

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Description

On night 1 I found out that I have a bunch of light leaks while taking darks, not good. So I didn't take darks on site.

On night 2 I tried out Ekos's automatic flat frame capture. During stacking, turns out those flats were worthless. Had to re-shoot them at home, but hey, I learned how to use this feature in Ekos.

I had to wrap the back of my telescope in a blanket to avoid light leaks. I need to rethink how to avoid this problem in the future.

Dithered only in RA axis, so some walking noise is still present. I will need to rethink how to address this issue, maybe I need to get some counterweights for DEC.

Even though guider focus wasn't perfect, I'm very happy with guiding. I had to throw out 0 frames. However, this may change when I introduce dither in DEC, which has a bunch of backlash.

Acquisition:

Lights: 101 * 180 sec, ISO 800

Dark: 8 * 180 sec, ISO 800

Bias: 30 * 1/32000 sec, ISO 800

Flat: 12 * ~1 sec, ISO 100 (method: http://www.whitedisplay.com/ and a tablet)

Stacking in DSS:

Drizzle x2

> Light

RGB channels background calibration: yes

Method: Kappa-Sigma (Kappa = 2.00, Iterations = 5)

> Bias

Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)

> Dark:

Method: Median

Dark Optimization: No

Hot Pixels detection and removal: Yes

> Flat

Method: Median Kappa-Sigma (Kappa = 2.00, Iterations = 5)

Processing in Photoshop:

* Initial stretch (Levels, Curves)

* 16 bit mode

* Crop

* (Gradient xTerminator) coarse, low aggressiveness, no color balance

* (Astronomy Tools) Color Blotch Reduction

* 3x (Astronomy Tools) Increase star color*

* (Astronomy Tools) Enhance DSO and Reduce Stars*

* (Astronomy Tools) Space Noise Reduction*

* (Astronomy Tools) Local contrast enhancement

* (Astronomy Tools) Soft color gradient removal

* Final strecth (Levels, Curves)

* (Gradient xTerminator) fine, medium aggresiveness

* Increase Saturation and Vibrance by a couple %

*) I had to modify these Astronomy Tools actions, because they use specific radius size. For 2x drizzle, they didn't work properly. I copied some of the actions and bumped all subactions that used "Radius" parameter to 2.5x the radius. I also had to modify "Select Brighter Stars" action, because some other actions depend on it.

Processing in Lightroom:

* Saturation and Vibrance by +15%

* Texture -17

* Blacks -5

Comments

Sky plot

Sky plot

Histogram

Markarian's Chain, Michał Kostrzewa