HA/LRGB tutorials

[Andyk93]

Hi, does anybody know where I can find good tutorials for pixinsight processing of HA images and LRGB. Light vortex astronomy do good tutorials but there is no workflow to follow through. I am struggling in what order to do things. The images I am processing are from an neq6 + star71 + atik 383l+ at -15c. The focus I think is very slightly off but here is 6 x 600s of m42 nothing done to it apart from calibrated and stretched to show detail. If I can get the images processed I don't think my results will be too bad, I think I’m finally getting reasonably good data

Thanks, Andy

[Pieter]

Quote

I think I’m finally getting reasonably good data

You can say that again! That looks great to work with.

I can't help you with the tutorials though but I will surely keep an eye out for the answer because I could use those as well

[ollypenrice]

I add Ha to LRGB in Photoshop. I can't help in PI but it seems that Harry Page, that excellent man, can take you through it...

http://www.harrysastroshed.com/pixinsight/pixinsight video html/pixinsighthomeinter.html

It's the fourth tab down.

Olly

[Andyk93]

9 hours ago, Pieter said:

You can say that again! That looks great to work with.

I can't help you with the tutorials though but I will surely keep an eye out for the answer because I could use those as well

Thanks very much! It’s taken a lot to get to this point

[ampleamp]

In addition to Harry(+10), try the Pixinsight's own YT video - https://www.youtube.com/watch?v=zqhLKIjGMXA&feature=related it usually rides straight into the second part

Adding Ha to LRGB, try https://www.youtube.com/watch?v=QYzNmx7KOGA

And adding RGB to Ha, i was pointed in the direction of two scripts - NBRGBCombination and HaRVB-AIP (got to download and add this one).

 

[Andyk93]

3 hours ago, ollypenrice said:

I add Ha to LRGB in Photoshop. I can't help in PI but it seems that Harry Page, that excellent man, can take you through it...

http://www.harrysastroshed.com/pixinsight/pixinsight video html/pixinsighthomeinter.html

It's the fourth tab down.

Olly

Thanks Olly

[Andyk93]

3 minutes ago, ampleamp said:

In addition to Harry(+10), try the Pixinsight's own YT video - https://www.youtube.com/watch?v=zqhLKIjGMXA&feature=related it usually rides straight into the second part

Adding Ha to LRGB, try https://www.youtube.com/watch?v=QYzNmx7KOGA

And adding RGB to Ha, i was pointed in the direction of two scripts - NBRGBCombination and HaRVB-AIP (got to download and add this one).

 

Thanks, what I’m struggling with is the actual workflow of things, I know I should be cropping to the exact same sizes but after that I’m stuck on what is the next process, and the next after that 

[Filroden]

For a good walkthrough, I’d recommend https://www.firstlightoptics.com/books/inside-pixinsight-book.html which is also available as an ebook. Though the Light vortex astronomy tutorials are shown in a workflow order though not all steps are always needed.

[ollypenrice]

...but for all this I'd still do it in Photoshop! 

lly

[ampleamp]

Someone will be along shortly with vastly more knowledge than i have but  as a basic workflow I tend keep reasonably on track with the following. Try and go for a minimalist approach; everything is a trade-off and just because you have the tools doesn't mean you have to use them all. I took quite a while to not be afraid to experiment - it sounds stupid but fear of not getting it right having spent a considerable amount of time acquiring data definitely hamstrung me; now i am a lot less inhibited and try things just for the hell of it sometimes. I would write down what works for you; if you are like me you will see something and then later wonder how you got there ;-) There are plenty specialised features within Pixinsight but if ever there was a programme to get the basics right...

 

DON'T OVER DO IT!

Dynamic Crop crop all four masters the same. Pick the master with the largest stacking edges. Define what to crop, but before you apply it, drag the little triangle to the workplace. Then apply and close Dynamic crop.

Open the next master and apply the same dynamic crop to it. Do this for the two remaing masters.

Combine RGB using ChannelCombination

Apply DBE to the RGB image. Save the icon on the workplace. Set DBE to subtract though can try DBE twice, first with division to handle the vignetting, then with subtraction to handle the gradient.

Background Neutralisation

Colour Calibration

See if the Luminance master can use the same DBE settings. If so, apply the previous DBE instance also to Lum, otherwise use a new DBE.

Noise reduction in the RGB image. Either use TGVDenoise or MLT noise reduction on 5 or 6 layers. GO EASY!

Stretch using HistogramTransformation. (More using masked Stretch, or a combination now)

Extract L for a luminance mask (copy of Lum master and apply STF stretch permanently). Make sure that the background is black in this mask, and the target quite bright.

Apply mask and use Curves to enhance colour saturation of the target and stars. Then set aside RGB

Deconvolution on Luminance - https://www.youtube.com/watch?v=ZLef9GlHLrs

Noise reduction on Luminance, usually TGVDenoise, but sometimes MLT works better. TGVDenoise is better at keeping faint detail. Use a stretched luminance copy as support. 

Histogram transformation. 

Repeat to finetune stretch.

Multiscale HDR Transformation to handle dynamic range.

Combine Luminance with RGB using LRGBCombination. 

ACDNR on chroma with a luminance mask protecting the target.

Star reduction using a contour mask and Morphological Transformation.

Final stretch or CurvesTransformation for better control.

[Andyk93]

2 hours ago, ollypenrice said:

...but for all this I'd still do it in Photoshop! 

lly

I wish I knew how to use it! The images I have seen of yours are what makes me interested in astrophotography 

[Andyk93]

2 hours ago, ampleamp said:

 

Thanks a lot! I’ll give it a go and post up the image

[ollypenrice]

11 hours ago, Andyk93 said:

I wish I knew how to use it! The images I have seen of yours are what makes me interested in astrophotography 

Do you have Ps? If so, work with a co-registered Ha image stretched even a tad beyond what you'd do with a standalone Ha (because the faint parts with the noise won't be going into the final image.)

Split the RGB or LRGB into its channels and paste the Ha onto the red layer.

Change the blend mode from 'normal' to 'lighten' in Layers.

Flatten. That's about it. (The only real refinement lies in fine tuning the Ha in Curves before flattening it down onto red.)

Olly

[Andyk93]

I do have ps so will have a go when I get enough data, thanks Olly. So here is 1hour30 9 x 600s of HA on the horsehead. I know it needs more data and I am aiming for 10 hours by the end of the year. This is my first go at processing a HA image.