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M45 - My first LRGB image to be published: Feedback?

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#1 Kevin Thurman

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Posted 23 September 2020 - 12:44 AM

Here is my first full attempt at an LRGB image. I've spent the last day and a half processing as I've been really learning how to use pixinsight as well. I have to step away at this point and clear my mind but I thought I'd post here to see if anyone has feedback I can apply tomorrow.  It's about 3 hours total from my first long dark sky trip, split evenly between L and RGB time. Most of the clear time was spent on M31 (about 3x as much), so I expect that image will come out better in the end than this, but I like what I am seeing so far. 

Can't seem to compress enough to upload it here without compromising the usability of this image as a feedback tool, so I hope this dropbox link works.
https://www.dropbox....rsion8.jpg?dl=0


Equipment:
RedCat 51
ASI183MM-Pro
ZWO EFW
Chroma LRGB
ZWO Guide scope & Cam
Skyguider Pro


Processing Steps:
1. After integration, I noticed a bad star bloat in the red channel. To me it looks like a focus issue, but that's odd because I meticulously checked focus just before as well as in the middle of the RGB sequence and the other two channels aren't out at all. I also shot the frames over multiple nights so something else is at play (unless the bahtinov is wrong about the red channel only?) So I focused on masking the stars and then shrinking them in the red channel with MorphologicalTransformation before RGB combination. It helped a bit but not as much as I wanted. I spent most of the time on generating masks.

2. After RGB combination I applied aggressive RGB noise reduction with MultiscaleLinearTransform and set the RGB aside.

3. sharpened the L channel using a star mask

4. Applied a less aggressive lum noise reduction to L

5. Finalized stretches before LRGBCombination

6. Final touches to stretches and to saturation before exporting and uploading to dropbox.

Thanks for viewing.


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#2 F.Meiresonne

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Posted 23 September 2020 - 12:58 AM

Nice image!

 

Especially when one considers the aperture...


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#3 imtl

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Posted 23 September 2020 - 01:26 AM

Why save it as jpg? You're ruining your image. Save as png or tiff.


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#4 Kevin Thurman

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Posted 23 September 2020 - 12:16 PM

Why save it as jpg? You're ruining your image. Save as png or tiff.

I'll upload a png as well, i just did that to save people a huge download.

#5 limeyx

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Posted 23 September 2020 - 12:25 PM

Nice image !


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#6 Kevin Thurman

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Posted 23 September 2020 - 01:03 PM

 This link should take you to a PNG version. I made a slight levels adjustment in GIMP after viewing the image on more screens.

https://www.dropbox....rsion8.png?dl=0



#7 droe

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Posted 23 September 2020 - 09:42 PM

I hope you dont mind but I played with your data a little bit. You have an insane amount of detail in your image. It is one of the best I have seen. Awesome job.

Attached Thumbnails

  • M45Version8NS.jpg

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#8 Kevin Thurman

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Posted 23 September 2020 - 11:09 PM

I hope you dont mind but I played with your data a little bit. You have an insane amount of detail in your image. It is one of the best I have seen. Awesome job.

Thanks! I like your processing too. 


I've posted what I consider to be the "final" image on astrobin now. Of course I can always upload revisions but this will be the version my friends and family see on social media, so it is in that way at least a little bit "final" Stay tuned for my M31, which has about twice as much data. I might wait to publish that until I can shoot h-alpha to add to the red channel, but I might not be patient enough for that.

https://www.astrobin.com/k4qylu/

 


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#9 TareqPhoto

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Posted 24 September 2020 - 07:19 AM

Wonderful image, no wonder to have such a beautiful image under Bortle 3, i feel i will never get good M45 under Bortle 8/9 even with very long time integration, great job there.


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#10 GiorgioF

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Posted 24 September 2020 - 10:49 AM

This is a really noticeable shot! A lot of wonderful details! Would you mind to share also some imaging data like how many light, duration of each, bortle sky,....? This will help me a lot and learn more.
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#11 Kevin Thurman

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Posted 24 September 2020 - 12:17 PM

This is a really noticeable shot! A lot of wonderful details! Would you mind to share also some imaging data like how many light, duration of each, bortle sky,....? This will help me a lot and learn more.

Details are in the astrobin page but ill briefly summarize here:
L: 50x 120s at gain 0
RGB: 10x 180s each channel at gain 130
60 darks each
25 flats each
100 bias for each gain setting
Sensor temp -10C

#12 GiorgioF

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Posted 24 September 2020 - 11:25 PM

Apologies Kevin, as was unable to take my eyes out of the picture, I didn't note the link.
It's really amazing the quantity of tiny filaments and details from the nebulosity
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