L-enhance / how to mitigate the lack of colors - Forums

Topic starter

Jun 1, 2021

Hi Folks!

I have been using a L-Enhance filter with my Redcat51 (and a ASI533MC camera) for a few months and really enjoy how it highlights the emission nebulas.
But, as it's a narrowband filter, it will cut most of the light and the stars lack often color. Usually I end up with white or grey stars and a nice red Nebula. Even playing with saturation on a star mask won't reveal color when they have been blocked by the filter (in particular the yellow stars).

Have you tried to mix an image taken with no filter (to get the star color) and mix it with the image taken with the L-enhace filter (mostly for the nebula)? Or is it just the price to pay for this kind of filter? Any magic recipe for us who use a color camera?

See below a typical example where the filter has highlighted the emission nebula but the stars look a bit dull....

For info, I use Siril (for the color callibration), Photoshop to strech the histogram, Starnet to enhance the Nebula and AI denoise... to reduce the noise and sharpe the image.

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Dale Penkala

Jun 1, 2021

Hi Folks!

I have been using a L-Enhance filter with my Redcat51 (and a ASI533MC camera) for a few months and really enjoy how it highlights the emission nebulas.
But, as it's a narrowband filter, it will cut most of the light and the stars lack often color. Usually I end up with white or grey stars and a nice red Nebula. Even playing with saturation on a star mask won't reveal color when they have been blocked by the filter (in particular the yellow stars).

Have you tried to mix an image taken with no filter (to get the star color) and mix it with the image taken with the L-enhace filter (mostly for the nebula)? Or is it just the price to pay for this kind of filter? Any magic recipe for us who use a color camera?

See below a typical example where the filter has highlighted the emission nebula but the stars look a bit dull....

For info, I use Siril (for the color callibration), Photoshop to strech the histogram, Starnet to enhance the Nebula and AI denoise... to reduce the noise and sharpe the image.

I can’t answer your question but letting you know that I’m following this as I have just acquired the same filter and have noticed that star colors are off as well. However I think that as you stated thats the price we pay but thats just a guess so it will be interesting to see if there is a good process for it.

Dale

Stefan Böckler

Jun 1, 2021

You could also use the l-eNhance data exclusively for luminance and gather some unfiltered RGB data and use this for color (chrominance) only. Thus, you would end up with nebulosity with high SNR, tight stars and natural looking colors. I tried this with this image of the flaming star nebula (have a look at the original version; final version D is l-eNhance H(HO)O color with some RGB stars).

The Flaming Star Nebula

Regards
Stefan

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Doversole83

Topic starter

Jun 1, 2021

Thank you all, lots of good suggestions there to try.

@Stefan Böckler thanks for sharing, it worked well on the Flaming star indeed.

I will definetly gather some data with both the L-Enhance and broadband to try a few of these methods out.

Jared Holloway

Jun 1, 2021

I have mixed data from both the L-eNhanced, the L-Pro and unfiltered and been able to have some better star color. I have only done it on a couple of targets. Most of my data came from the L-eNhanced and then I had 2-3 hours with the L-Pro and no filter at all.

Doversole83

Topic starter

Jun 3, 2021

I will try mixing data from L-enhance and broadband (IR-UV filter) on a target like Sadr in Cygnus I know I will get all summer long.
Happy to share some data and feedback here.
I also saw an interesting tutorial by Astrobackyard on how to create a composite image from a RBG and an H-Alpha images.
I feel I need to find a way which would be a nice balance between the amount of additional work (I don't want to end up with something more time-consuming than a mono camera!) and added value.

Let's hope for some clear skies!

Tom Marsala

Jun 4, 2021

The L-Enhance has been a game-changer for me using my modified DSLR. In fact, my star colors are very good (IMHO) with this filter. I use photoshop exclusively for post, so I know I am far from professional here, but after I isolate the stars in a mask I am able to do a color enhancement on just the stars and the color pops very well. I don't know if aperture has anything to do with it, but I am able to capture a lot of color with my 13.1" mirror. But I do like Jared's idea of combining the L-pro with the L-enhance. I need to try that!

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estabrook

Jun 4, 2021

I like the idea of combining a narrowband L-Enhance image with a broadband-Pro image. I've ordered both filters, and they are both on back-order, but I hope to try this out soon!

Well Written

Dale Penkala

Jun 4, 2021

I’m going to pick up an L-Pro and give that a try as well! I have the L-Enhance. I’m not very good at processing so combining both data sets I’m not sure how to do that but I guess when I get to that point I’ll post something about how thats done and hopefully I can get some guidance in that process.

Dale

Paul Macklin

Jun 4, 2021

Perhaps try the calibrate star color tool in APP.

Dale Penkala

Jun 5, 2021

Paul Macklin:
Perhaps try the calibrate star color tool in APP.

Umm what is APP???

Paul Macklin

Jun 5, 2021

Sorry, that's astro pixel processor, if you have it.

Dale Penkala

Jun 5, 2021

Paul Macklin:
Sorry, that's astro pixel processor, if you have it.

No worries, I don’t have that one.

Thanks though!

Tom Gray

Jun 5, 2021

Dale Penkala:
I’m going to pick up an L-Pro and give that a try as well! I have the L-Enhance. I’m not very good at processing so combining both data sets I’m not sure how to do that but I guess when I get to that point I’ll post something about how thats done and hopefully I can get some guidance in =16px ***

Dale Penkala:
I’m going to pick up an L-Pro and give that a try as well! I have the L-Enhance. I’m not very good at processing so combining both data sets I’m not sure how to do that but I guess when I get to that point I’ll post something about how thats done and hopefully I can get some guidance in that process.

Dale

Hi Dale, there are some useful posts on the forums for doing this with Startools. I use the L(eNhance) RGB method with my mono camera. You can also mix data from OSC camera in the compose module to produce a variety of colour interpolations. Have fun.

Well Written Concise

Dale Penkala

Jun 5, 2021

Tom Gray:
Dale Penkala:
I’m going to pick up an L-Pro and give that a try as well! I have the L-Enhance. I’m not very good at processing so combining both data sets I’m not sure how to do that but I guess when I get to that point I’ll post something about how thats done and hopefully I can get some guidance in =16px ***

Dale Penkala:
I’m going to pick up an L-Pro and give that a try as well! I have the L-Enhance. I’m not very good at processing so combining both data sets I’m not sure how to do that but I guess when I get to that point I’ll post something about how thats done and hopefully I can get some guidance in that process.

Dale

Hi Dale, there are some useful posts on the forums for doing this with Startools. I use the L(eNhance) RGB method with my mono camera. You can also mix data from OSC camera in the compose module to produce a variety of colour interpolations. Have fun.

Thanks for the info Tom! I’ll check that out!

Dale

Stefan Böckler

Jun 5, 2021

Hi everybody! I had the chance to try adding some broadband data to l-eNhance stuff one more time. After doing an Hubble palette mimic/fake (call it what you want) in StarTools (which has been already mentioned by @Tom Gray) I used a star mask to just drop the colors of the RGB stars into the narrowband image.

The Crescent Nebula NGC 6888

IMHO the RGB stars added some value to the final image, since the stars are less uniform. I start to like this kind of combinations.

By the way: For the RGB stars I stacked 4 hours of broadband data. The amount of signal (or rather the lack of it) compared to the l-eNhance data was striking. In my eyes, combining both kinds of data lets you get the best of both worlds - nice SNR and natural looking colors (or at least star colors).

Clear skies to you and good luck with your projects!
Stefan

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Doversole83

Topic starter

Jun 10, 2021 · Edited: Jun 10, 2021

So I did a trial on the Sadr region using my usual Redcat 51.
First image was done using an L-enhance filter. Post-processed as usual (Siril, Photoshop, Starnet++, Denoise AI).
Second image (last night) with just an IR + UV cut filter. Post processed in Siril (color callibration), PS (histogram strech)

Then:
1. I aligned both images in PS. (I used the master L-enhance as a reference in DSS but somehow it failed to align...)
2. Extract the RED chanel of the L-enhance image (basically the H-Alpha channel) and blend it the the Red channel of the RGB image to recreate a new red chanel for the RGB image
3. Use the L-enhance as a luminance layer
4. Play a bit with curves

I believe I got what I wanted. The Nebulas are highlighted thanks to the narrowband filter and stars have colors thanks to the RGB image.
Comments welcome!

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Stefan Böckler

Jun 10, 2021

This looks pretty good to me, it's a really nice composition in my eyes!

Can't say much about your workflow except for aligning the images. I don't use DSS much anymore, but I had the same problem that using the first stack as a reference frame the software would not align the second stack correctly. Therefore, I choose a single frame from l-eNhance data as a reference frame for the l-eNhance stack and the exact same l-eNhance single frame as a reference frame for the broadband data. Do not forget to UNCHECK the single frame in your list this time, unless it will get stacked and mixed with the broadband frames. But even if it's unchecked, it will still be used as a reference frame.

This always worked for me. Thus you will have images aligned by DSS which will presumably yield better results than aligning the stacks manually in PS. Hope that helps!

Best regards
Stefan

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Robert Eder

Jun 10, 2021

Hi,
I use in most of my nebula images a mix of RGB and HOO from the L-enhance filter. I stack the dual band as a normal color image. After star alignment I remove the stars with starnet++. The mix of RGB and HOO I do in Photoshop. I split the dual band into red, green and blue -mono files. I set the layer to blendmode "screen" and with a "hui/saturation layer in colorize mode" I mix the Ha in red and O3 in green and blue into the RGB. I really like the broadband color with the enhanced narrow band look.

Here are some examples:

RGB HOO mix

Starless dual band from L-enhance

CS, Robert

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Tom Marsala

Jun 10, 2021

Those are beautiful! Gives me inspiration for future processing

Dale Penkala

Jun 10, 2021

This is all great stuff! I just had a run on M16 last night that yeilded 4hrs and I’m hoping that I can have another good run yet tonight! I’m using the L-enhance filter as well and so far liking what I’m getting out of it.
I just ordered the L-Proa form Starzona yesterday and I’m hoping that if I take a run of images with the l-Pro and l-enhance and somehow combined them that maybe the stars will yield a bit more natural color. Don’t know but guess we will see. 1st I have to figure out how to combine the images! 🤣

Dale

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Doversole83

Topic starter

Jun 14, 2021

@Robert Eder , thanks a lot for sharing!
I am exploring your method on IC1396, the Elephant's trunk nebula.
I understand how you separate your dual band starless image into 3 channels. Same with the boradband RGB. For each channel, I have mixed the RGB broadband and HOO using screen mode. But how do you add a "hui/saturation layer in colorize mode" and to what purpose?

Thanks for helping a noob!!

A first trial using an L-enhace image 46x180s and a broadband image 89x120a of IC1396 using a Redcat 51. It's nice to see some more colorfull stars.

Tom Gray

Jun 14, 2021

Nice! There is a really useful discussion on using the L-eNhance for L and broadband RGB in the Startools forum HERE.

Dave B

Jul 5, 2021

Startools v1.8 which is currently in beta stage has a new module called Nbaccent so you use compose module to load lrgb channels from unfiltered data then load narrow band data from say duo band filter , as you process image and after you use the colour module you use the nbaccent module and it will blend the nb data to image , it works very well , I have a zwo533mc coming this week so hopefully I will be able to try out with my own data, 1.8 should be ready for public release very soon , there is also a new deconvoloution algorithm which is outstanding, check out the Startools forum for more info .

any zwo533mc users what gain / offset settings do you use

Steven

Jul 14, 2021

interesting topic. I'm not that familiar with colour imaging yet, I've mainly shot mono so far.
But I have now completed my second rig, which will shoot full colour (once the weather allows it)

I'm using a similar setup

Redcat
ZWO ASI 183MC
Optolong L-Extreme.

Waiting to see how that works, if I'm not happy with the colours, I might throw in my "Optolong L-Pro" which should allow a little more of the natural colours to come through, especially in the stars. And blend those in together