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adjusting the LRGB channels on my M33 image

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#1 Ballyhoo

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Posted 08 December 2019 - 10:03 PM

I have not been able to get the blue into M33 that I often see in other images, and so I decided to experiment by adjusting the channels in LRGB. I merely turned them down except blue, applied, then ran a range masked curve transformation. Boy with the mask inversion on it can really wipe out the noise presentation by just darkening the background and in this case I did not even run a noise reduction proc. But does this image pass the test, or is their too much blue in the background?  I suppose I could have masked the image prior to running LRGB but that is not how I learned to do it.  But then I never learned to do it by adjusting the indivual channels.

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  • m33 lrgb.jpg

Edited by Ballyhoo, 08 December 2019 - 10:08 PM.


#2 Salacious B Crumb

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Posted 09 December 2019 - 10:09 AM

I don't see any blue. although it's hard to tell from a small image like that. But I wonder if you wiped out some fainter arms also with your range mask. I think it's rather obvious where you mask has ended and where the transformation starts. I would try something less definite than a black and white range mask. Try extract the Lum from your image and if needed, play with the levels (gently) to get that more protective as needed.

 

 

- Mikko


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#3 Madratter

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Posted 09 December 2019 - 10:22 AM

On my website, I have an entire PixInsight tutorial on M33.

 

That said, and as mentioned in the tutorial, my method has changed over the years. I have found that in general it is best to do the L combination with already processed color by turning your processed color into CIELAB and then replacing the lightness channel.

 

But as mentioned I go into how I processed M33 in extensive detail in that tutorial. The dropbox links to my data probably no-longer work, but other than that, the tutorial should help.


Edited by Madratter, 09 December 2019 - 10:24 AM.

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#4 Ballyhoo

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Posted 09 December 2019 - 12:22 PM

well, how realistic does the coloring look in my image?



#5 bmhjr

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Posted 09 December 2019 - 12:27 PM

well, how realistic does the coloring look in my image?

It looks good.  I think M33 is one of those targets where you can find a wide range of color representations but the consensus seems to be how you have it.


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#6 Ballyhoo

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Posted 09 December 2019 - 12:54 PM

It looks good.  I think M33 is one of those targets where you can find a wide range of color representations but the consensus seems to be how you have it.

This is interesting. With stars, the colors are either correct or not. Stars have specific spectral classes.  I suppose it is not the same thing with galaxies but there will be stars in our galaxy images which should show the correct spectrum.

 

I don't see any blue. although it's hard to tell from a small image like that. But I wonder if you wiped out some fainter arms also with your range mask. I think it's rather obvious where you mask has ended and where the transformation starts. I would try something less definite than a black and white range mask. Try extract the Lum from your image and if needed, play with the levels (gently) to get that more protective as needed.

 

 

- Mikko

I am not sure what image you are looking at. mine is in #1.



#7 Madratter

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Posted 09 December 2019 - 01:00 PM

My opinion is that the way you processed it eliminated color that could have been brought out. For example, there is very little differentiation between the middle and the arms. Also, there is some beautiful star color in the frame that could have been brought out, but wasn't. Again, see my tutorial for what I am talking about.


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#8 Ballyhoo

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Posted 09 December 2019 - 02:00 PM

My opinion is that the way you processed it eliminated color that could have been brought out. For example, there is very little differentiation between the middle and the arms. Also, there is some beautiful star color in the frame that could have been brought out, but wasn't. Again, see my tutorial for what I am talking about.

your website helps convince me about going mono. But would an SBIG be an issue w SGP and ASCOM?


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#9 Madratter

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Posted 09 December 2019 - 02:14 PM

SBIG cameras work just fine with SGP. I am not currently able to use the camera with N.I.N.A even though I tried using Nebulosity 4 as a go between (Nebulosity 4 with the proper add-on can act as an ASCOM driver). In N.I.N.A I had problems where it would not connect because of the cooling portion and because of the filter wheel.

 

I have used SGP for years with my Camera and it has worked well. That said, I'm not real crazy about the fact they (SBIG) never have developed an ASCOM driver.


Edited by Madratter, 09 December 2019 - 02:15 PM.

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#10 Ballyhoo

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Posted 09 December 2019 - 02:34 PM

SBIG cameras work just fine with SGP. I am not currently able to use the camera with N.I.N.A even though I tried using Nebulosity 4 as a go between (Nebulosity 4 with the proper add-on can act as an ASCOM driver). In N.I.N.A I had problems where it would not connect because of the cooling portion and because of the filter wheel.

 

I have used SGP for years with my Camera and it has worked well. That said, I'm not real crazy about the fact they (SBIG) never have developed an ASCOM driver.

As much as SBIG is attractive - they are the first ones to put out a CCD camera back in the day, I will not be getting any camera that does not have ascom. So I am glad you let me know there is not one. I think it is just too limiting.

 

 

I have been considering the Meade DSI 4 mono camera. but even that one has issues w ascom. But atleast it has an ascom driver I am just not sure how it will work w SGP. It does not have enough users to get reports from.  But the price is right. $1000 for a mono camera and the same sensor as the 1600.



#11 Madratter

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Posted 09 December 2019 - 02:51 PM

As much as SBIG is attractive - they are the first ones to put out a CCD camera back in the day, I will not be getting any camera that does not have ascom. So I am glad you let me know there is not one. I think it is just too limiting.

 

 

I have been considering the Meade DSI 4 mono camera. but even that one has issues w ascom. But atleast it has an ascom driver I am just not sure how it will work w SGP. It does not have enough users to get reports from.  But the price is right. $1000 for a mono camera and the same sensor as the 1600.

I have zero knowledge of the Meade. I would be absolutely sure about the stability of the drivers. The sensor is only one part of the bigger system that makes up a camera. It is an important part, but so are the other pieces.


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#12 Ballyhoo

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Posted 09 December 2019 - 03:03 PM

I have zero knowledge of the Meade. I would be absolutely sure about the stability of the drivers. The sensor is only one part of the bigger system that makes up a camera. It is an important part, but so are the other pieces.

I agree with you 100%. I am trying to reach out to other owners of that camera. I originally purchased the OSC version and I had to return it because it was unstable. I have been told that since then there have been ascom upgrades but I am not sure how great the upgrades are.

 

Somewhat suprised that Meade, as large as it is, can not just have their coders spend some time and update the ascom driver. 



#13 Salacious B Crumb

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Posted 09 December 2019 - 05:39 PM

This is interesting. With stars, the colors are either correct or not. Stars have specific spectral classes.  I suppose it is not the same thing with galaxies but there will be stars in our galaxy images which should show the correct spectrum.

 

I am not sure what image you are looking at. mine is in #1.

Yes I can only see one image here. My respond of not seeing any blue was to this question; or is their too much blue in the background?

 

 

- Mikko



#14 Ballyhoo

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Posted 10 December 2019 - 02:06 AM

Right, I masked the background. I am happy to know I have much to learn.



#15 Night shift

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Posted 10 December 2019 - 02:49 PM

  Just because it has the same size sensor( or same sensor) does not mean the camear has the same quality build. I remember you saying you made a mistake on the first Meade you bought. So you are considering this one due to the $1000.00 price and sensor size??  That does not sound very savvy.  Buying buy price normally doesn't work.  And I do not see a lot of people using them. I don't know anything about the Meade so I will bow out on this subject. I would look on CN classifieds. Good luck in your purchase.


Edited by Night shift, 10 December 2019 - 02:50 PM.

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#16 Peter in Reno

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Posted 10 December 2019 - 07:30 PM

You didn't say you separated or extracted three separate RGB channels or images from OSC image BEFORE using LRGBCombination. If you didn't do this first, then LRGBCombination is not the correct tool for what you are trying to do. 

 

Peter 


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#17 pfile

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Posted 10 December 2019 - 07:33 PM

i think you've clipped the background too hard, there's a lot of details in the outer arms in your image which are now gone...

 

rob




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