Ngc7293

[PKay (Peter)]

I was surprised by this.
I think my tiny 85mm scope did well!

As always, please post your efforts from the past or present in this thread.
It is always great to compare, and a good way to learn.

38 subs @ 180s
Gain: 139 (unity)
10 Darks, Bias, Flats


For the PI & PS users.
I wrote out the process as much for my benefit as others.

PI Process:
Starting with Master Light (after batch processing).

STF - Screen Transfer Function. Apply.
ABE - Automatic Backround Extraction. Use Subtraction
SCNR - Remove green
BN - Background Neutralization
HT - Hystogram Transformation - Becomes Non Linear. Turn off STF.
CC - Colour Calibration. Create previews of light and dark areas for white and background reference.
CT - Curves Transform. Reduce Luminance and increase Saturation.
Save as XISF file
DC - Dynamic crop if needed.
Save as JPEG.

PhotoShop:
Color balance
Hue/Saturation
Vibrance
Curves
Levels
Brightness/Contrast
Save as new JPEG

[Sunfish (Ray)]

You did well. Hard to get those details and colours on a small scope. The cooled 1600 helps. Must be dark down at Depot.

[LostInSp_ce]

Impressive work Peter! However, looking at your workflow I'm curious as to why the double jpeg compression? Is it to save on hard disk space? The reason I ask is because you're essentially downsampling your colour depth before stretching it again in the final stages of processing.

[Ryderscope (Rodney)]

That result is very good Peter. Nice colours and good detail has come through. As far as workflow goes, I offer the following:

* Any cropping can be done first thing rather than towards the end of the process. This can help when using ABE/DBE as the process will only have to work on the relevant parts of the image. It also removes any black edges left over from the image registration and stacking process.

* Colour calibration is normally done at the linear stage, before stretching with the histogram tool.

* I don’t see any noise management activity in the workflow. This can be included after colour calibration and before the initial stretch. Additional noise management processes can also be applied later on in the workflow when the image is non linear.

* All of the steps mentioned that were executed in Photoshop can be completed just as well, if not better, in Pixinsight. It would be worth exploring these further in PI.

* If the image must be handed over to Photoshop for further fine tuning then save it as a 16 bit TIFF file so as to not lose resolution and quality by saving in a lossy format such as JPEG.

I hope that helps Peter. If you check out the site “Light Vortex Astronomy” he has some good tutorials that go through noise management, colour calibration and many other processes in PI.

Clear skies,
Rodney

[Fernando]

Hi Peter,


Nice picture. Like the colours and details.


Thanks for posting your PI workflow. I am still struggling with PI workflow. Read somewhere that if there are 3 different ways to process an image, you may choose one from the 18 in PI. I am trying to incorporate Deconvolution in the workflow and I am not able to see much after. Also, MorphologicalTransformation to reduce star sizes.


Got a book, online sofar, but will be in print soon, "Mastering Pixinsight", by Rogelio Berna Andreo. A great book in PI.



Regards, Fernando

[PKay (Peter)]

Thanks for the tips.
I am struggling after a 2 year hiatus. Life got in the way...