L-xtreme filter - Forums

Topic starter

Dec 8, 2020

Hello all my fellow L-xtreme filter users. I purchased the filter about a month ago and have posted a few images on this forum. My latest project was the Spaghetti Nebula ( Sh2-240). I have found that the filter performs really well with long exposures. I used 600 second subs with my ASI 071 mcPro and Samyang 135 mm @ f 2.8. My skies are Bortle 7-8. Some stars get halos around them though. But I have a technique to remove them in post processing. All-in-all, I really like this filter! I look forward to seeing everyone's images on this forum!
Clear skies, Mike

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Ivan Raichev

Dec 8, 2020

Hello. I have the filter since August this year and I am really happy with it. Makes my sky dark, my stars not that shiny and the HA really stands out. In my opinion I have achieved good results with it - at least I like what I see

I use it with the RASA8 and I have installed it by replacing the glass window directly on the scope. I use 2 and 5 minutes exposures.

I bought the filter right after I acquired my RASA8. I tried to image the Wizard Nebula without a filter and all I could see were stars - countless stars. The nebula was barely visible. With the filter the brightness of the stars dropped and the Nebula was clearly visible in HA.

However recently I read some reviews of RASA8 users where the filter does not let any HA in and there is no red in their exposures. This is strange for me and I am puzzled how this can happen.

If anyone asks - I recommend the L-Extreme with confidence because it performs excellent for me.

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Elmiko

Topic starter

Dec 9, 2020

Cool post Sektor! I've never heard about the Rasa not letting in any of the red channel. I've read on cloudy nights that this filter isn't optimal at F2. But it works fine for me using my Samyang lens at f2.8.

George C. Lutch

Dec 10, 2020

I've experienced the issue with the L-Extreme shifting the bandpass for Ha on my Hyperstar system. I know the filter works really well on my ES 127mm Refractor so it's a keeper. I found lots of folks out there that are recommending the new IDAS NBX filter for the faster F2 systems like RASA and Hyperstar so will likely get one when my ASI2600 comes back from china.

Elmiko

Topic starter

Dec 11, 2020

Hi George, I have yet to try the L-xtreme with my Hyperstar system. How does it effect the images by shifting the band pass? Not sure I totally understand.

George C. Lutch

Dec 11, 2020 · Edited: Dec 11, 2020

It reduces the light transmission of the Ha band for the most part to the point that it shows very little Ha Data. The OIII data shifts as well but for some reason not enough to affect OIII data as much. It actually takes me less time to shoot via the L-Extreme on my 127mm refracter and I get more data then on my Hyperstar with the L-Extreme.

Elmiko

Topic starter

Dec 12, 2020

Very interesting. Thanks for sharing this George. I will post my results using the L-extreme filter with the Hyperstar as soon as I image with the combo.

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Mau_Bard

Apr 6, 2021

Hi All.
I have just purchased an L-eXtreme to be used in association with my OSC camera (ASI2600MC).
I apologize for the very basic question: do you have any initial suggestions about post processing with PixInsight?

I start from the point that, when you split the channels of a L-eXtreme OSC image, you extract H-alfa and O-III respectively from red and green channels.

Now my basic questions are:
1. In a "pure" L-extreme scenario (no RGB signals) how could we recombine the H-alfa nd O-III signals in a pleasant way?
I have seen somewhere, for instance, the suggestion to assign the following palette:
R=O-III
G=H-alfa
B=H-alfa - O-III (do not ask me why the difference)

2. In a different scenario, where we want to mix H-a and O-III with R-G-B have you got any suggestions?

Thank you very much in advance for your help!

Mau

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Mau_Bard

Apr 7, 2021

Thank you @Allan Alaoui , for all your suggestions!
Because there are a lot of possibilities, it is good at the beginning to have a few "standard recipes", like the ones you provided here, as a safe harbor to start from.
Thanks again,

Mau

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Nicolas Eon

Nov 28, 2021

Hi All.
I have just purchased an L-eXtreme to be used in association with my OSC camera (ASI2600MC).
I apologize for the very basic question: do you have any initial suggestions about post processing with PixInsight?

I start from the point that, when you split the channels of a L-eXtreme OSC image, you extract H-alfa and O-III respectively from red and green channels.

Now my basic questions are:
1. In a "pure" L-extreme scenario (no RGB signals) how could we recombine the H-alfa nd O-III signals in a pleasant way?
I have seen somewhere, for instance, the suggestion to assign the following palette:
R=O-III
G=H-alfa
B=H-alfa - O-III (do not ask me why the difference)

2. In a different scenario, where we want to mix H-a and O-III with R-G-B have you got any suggestions?

Thank you very much in advance for your help!

Mau

Hi @Mau_Bard Thanks for your post

I like working in HaSHO space. I do image with DSLR and L-Extreme. Here is I usually proceed:
Ha = R
Oiii= 0.7G+0.3B
Siii= RGB Luminance

SHO I used the combination proposed by "The Coldest Nights" (https://thecoldestnights.com/2020/06/pixinsight-dynamic-narrowband-combinations-with-pixelmath/)

R = (Oiii^~Oiii)*Sii + ~(Oiii^~Oiii)*Ha
G = ((Oiii*Ha)^~(Oiii*Ha))*Ha + ~((Oiii*Ha)^~(Oiii*Ha))*Oiii
B = Oiii

as PI Math expression

Then I add Ha as Luminance channel. Finally, I do Curve Transformation to find the right colours.

I am still learning in this process as my post processing does not seems to be predictable. If I repeat several time the same workflow, I may end with different results. Maybe this due to the stretch of my different channel which change the colour balance of my final image.

Does anybody knows how can I make sure that each channel (Ha, Sii and Oiii) are stretched separately but in a consistent way ?

Helpful

Mau_Bard

Nov 28, 2021

Hi Nicholas,
and thanks for your answer.
After trying different methodologies with mixed results, I eventually landed on the processing well described by lukomatico in his youtube video below.
I find it extremely robust and consistent. Here is the link https://www.youtube.com/watch?v=QV6ObLVRvNk

It is substantially based on the utilization of strong signal channels R and G only (starless), equalization of G with R intensity (very important!), and then a very simple new channel assignment, well illustrated in the video.

I strongly recommend to follow this processing that was generously shown me by the expert @Elmiko,, whom I'll never stop to thank.

Hope you will enjoy this methodology!

All the best!

Mau

Nicolas Eon:
Hi All.
I have just purchased an L-eXtreme to be used in association with my OSC camera (ASI2600MC).
I apologize for the very basic question: do you have any initial suggestions about post processing with PixInsight?

I start from the point that, when you split the channels of a L-eXtreme OSC image, you extract H-alfa and O-III respectively from red and green channels.

Now my basic questions are:
1. In a "pure" L-extreme scenario (no RGB signals) how could we recombine the H-alfa nd O-III signals in a pleasant way?
I have seen somewhere, for instance, the suggestion to assign the following palette:
R=O-III
G=H-alfa
B=H-alfa - O-III (do not ask me why the difference)

2. In a different scenario, where we want to mix H-a and O-III with R-G-B have you got any suggestions?

Thank you very much in advance for your help!

Mau

Hi @Mau_Bard Thanks for your post

I like working in HaSHO space. I do image with DSLR and L-Extreme. Here is I usually proceed:
Ha = R
Oiii= 0.7G+0.3B
Siii= RGB Luminance

SHO I used the combination proposed by "The Coldest Nights" (https://thecoldestnights.com/2020/06/pixinsight-dynamic-narrowband-combinations-with-pixelmath/)
R = (Oiii^~Oiii)*Sii + ~(Oiii^~Oiii)*Ha
G = ((Oiii*Ha)^~(Oiii*Ha))*Ha + ~((Oiii*Ha)^~(Oiii*Ha))*Oiii
B = Oiii

as PI Math expression

Then I add Ha as Luminance channel. Finally, I do Curve Transformation to find the right colours.

I am still learning in this process as my post processing does not seems to be predictable. If I repeat several time the same workflow, I may end with different results. Maybe this due to the stretch of my different channel which change the colour balance of my final image.

Does anybody knows how can I make sure that each channel (Ha, Sii and Oiii) are stretched separately but in a consistent way ?

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Elmiko

Topic starter

Nov 28, 2021

I'm hardly the expert….. That's Lukematico…😆
Thanks for the shout out though, Mau.

Mike