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PixInsight : Dynamic narrowband combinations with PixelMath


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While my mount is out of action for a few weeks, I decided to reprocess some old data taken last year, using dynamic narrowband combinations found here. The process requires the SHO data to be stretched before combining, then continue with your normal workflow. The result is pretty impressive as you can see below. The final image was obtained combining a normal SHO combination, and the dynamic combination. I used a 50/50 mix in Pixelmath. The top image is a normal SHO combination, the second image is the SHO/dynamic SHO combination.

 

2099967958_SoulNebula.thumb.jpg.d7778a071838328cbfeba75d52b4c190.jpg

 

1371397241_DynamicSHO.thumb.jpg.f17a20931d4a8b4e8962ec8f68b58ccb.jpg

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Big difference, I must confess I do stretch my Ha, Oiii, and Sii separately before combining, mainly because they are so much fainter than Ha and need different amounts of stretching.

 

They are both nice, but the 2nd one certainly has a lot more detail.

 

Carole 

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8 minutes ago, Carastro said:

Big difference, I must confess I do stretch my Ha, Oiii, and Sii separately before combining, mainly because they are so much fainter than Ha and need different amounts of stretching.

 

They are both nice, but the 2nd one certainly has a lot more detail.

 

Carole 

Thanks Carole. I used a new workflow on these stacks, I removed the noise before stretching, which I never do normally and also used the Ha data as luminance for the extra detail. I prefer the second one myself, the colour is a lot richer, and has a lot more depth to it.

 

Brian

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1 minute ago, Jkulin said:

Lovely image and details Brian

Thanks John. I tried out Ez Denoise and EZ Decon on this image. Both produced excellent results, and far easier and quicker than using the conventional methods. The Ez Denoise in particular, did a fantastic job, although I did use a little bit of ACDNR later in the process after curve adjustments.

 

Brian

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2 hours ago, AstronomyUkraine said:

 and also used the Ha data as luminance for the extra detail. I prefer the second one myself, the colour is a lot richer, and has a lot more depth to it.

 

Brian

Yes I do that too.

Carole 

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2 hours ago, AstronomyUkraine said:

Thanks John. I tried out Ez Denoise and EZ Decon on this image. Both produced excellent results, and far easier and quicker than using the conventional methods. The Ez Denoise in particular, did a fantastic job, although I did use a little bit of ACDNR later in the process after curve adjustments.

 

Brian

Yep Brian, I use the EZ tools a lot and the star reduction algorithms were created by Adam Block.

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2 hours ago, MarkAR said:

Wow, big difference. I actually like both equally, they show different moods to the image.

 

This technique certainly makes a difference to the normal SHO combination. Going to try it on a HOO image to see if it improves those too.

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Posted (edited)

This is the same dynamic combination process used on HOO data. The PixelMath formula is different, but the processing is exactly the same. Instead of mixing the HOO and dynamic HOO in a 50/50 mix, this combination was 30/70. The top image is the usual HOO combination. The second image is the HOO/dynamic HOO mix. The most startling difference, besides the colour, is the amount of detail in the second image compared to the first one. The background nebulosity is also more prominent.

 

HOO.thumb.jpg.1acf7be91ab66ee3ea5266dc6300aeaa.jpg

 

Dynamic_HOO.thumb.jpg.cf62f5b58cf1587dbb0a04727b9e54ec.jpg

 

 

Edited by AstronomyUkraine
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1 hour ago, MarkAR said:

Amazing difference. It's almost like the first image has discarded much of the nebulosity as noise.

I was amazed myself, and both images had the same simple stretch with STF and HistogramTransformation.

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