Processing images taken with Optolong l-Enhance filter - Forums

Topic starter

May 27, 2021 · Edited: May 27, 2021

Hello Everyone,
I was out last night nearly full moon and decided to try out my new l-Enhance filter on the Iris nebula. I new that the filter cuts a lot of light so I added longer exposure time to help off set for that. I know that this filter is not good for galaxy, but from my understanding its good for nebula’s specifically emission nebulas so maybe the Iris wasn’t the best target to try out this filter. Anyway I have heard that it can be difficult to process images when these filters are used. Boy was that a true statement!

Can any of you describe your process for processing an image when this filter was used to acquire the data? I use a OSC ZWO ASI294mc Pro CMOS camera.

Thanks in advance!

Dale

Rob Kiefer

May 27, 2021 · Edited: May 28, 2021

The Iris Nebula is a reflection nebula and the l-Enhance is not going to work for this kind of nebula. So I agree, the Iris is not the target to try this filter. Try it on e.g. NGC 7000 and you will see the difference.
In principle, I do the following, take subframes without the filter, then with the filter. Stack the two sets separately. After processing the two sets, I blend the two images together (filter image as background).
Rob

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DanRossi

May 28, 2021

The Iris Nebula is a reflection nebula, meaning it reflects broadband light from nearby stars, so the L-enhance definitely isn't meant for that target. It's meant for emission nebula as you said, so its best used on targets like the Rosette Nebula, North America Nebula, Crescent Nebula, Elephant Trunk Nebula, Lagoon Nebula, and so on (targets primarily composed of H-Alpha and OIII). Free software like Stellarium can help you find targets in the sky and tell you their composition.

I'm not surprised you had a difficult time because you most likely blocked out most of the broadband signal. Don't get discouraged this stuff can be a lot to learn and everyone on this site has struggled a bit…I would bet.

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Dale Penkala

Topic starter

May 28, 2021

Thanks Nova4! I plan to use it on many emission nebulas this summer! I was in that area so I thought I’d give that one a try. Again bad choice.

Dale

Elmiko

May 28, 2021

Yes, the Iris is a reflection Nebula. Try the L-eNhance filter on M8 or The Elephant Trunk.

Dale Penkala

Topic starter

May 28, 2021

Elmiko:
Yes, the Iris is a reflection Nebula. Try the L-eNhance filter on M8 or The Elephant Trunk.

Thanks! I will be doing so next time out!

Is there any processing differences for images taken with a filter like this?

Dale

Tom Gray

May 28, 2021 · Edited: May 28, 2021

Hi Dale I use one of these for my old Meade OSC camera. I now use it on my mono camera, really to sharpen luminance frames or Ha/OIII in emission and planetary nebulae.

I have found processing fairly straightforward in Startools, although OIII data does tend to be noisy in bright moonlight due to the fairly wide 35nm band pass. The 24nm Ha component is easier.

With a mono camera you can integrate the L-eNhance data with R and B for a more natural ‘duo band’ image.

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Dale Penkala

Topic starter

May 28, 2021

Tom Gray:
Hi Dale I use one of these for my old Meade OSC camera. I now use it on my mono camera, really to sharpen luminance frames or Ha/OIII in emission and planetary nebulae.

I have found processing fairly straightforward in Startools, although OIII data does tend to be noisy in bright moonlight due to the fairly wide 35nm band pass. The 24nm Ha component is easier.

With a mono camera you can integrate the L-eNhance data with R and B for a more natural ‘duo band’ image.

Hello Tom,
Thanks for the reply, Well that explains why there is so much noise! I read that it was used during nights with a more fully lit moon to help block its light and give more contrast to the object your imaging. Either I misunderstood or they did know what they were talking about.

I had to stretch the data and make a lot of color corrections to even get it to look “somewhat” close to what it does without the filter and then ended up with a HUGE amount of noise. Was thinking that I should get rid of it, but I’ll maybe try it on some more suitable targets.

I use a OSC camera so I don’t know that I can do intergration thing. Even if I could I wouldn’t know the 1st thing about how to do it.

Thanks again for your response Tom!

Dale

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Dale Penkala

Topic starter

May 28, 2021

Rob Kiefer:
The Iris Nebula is a reflection nebula and the l-Enhance is not going to work for this kind of nebula. So I agree, the Iris is not the target to try this filter. Try it on e.g. NGC 7000 and you will see the difference.
In principle, I do the following, take subframes without the filter, then with the filter. Stack the two sets separately. After processing the two sets, I blend the two images together (filter image as background).
Rob

Hello Rob,
I will give your suggestion a try. I’ve never blended 2 images together unless you are talking about “merge” layers (I use Gimp).
I didn’t know that you shoot it with and without the filter either so thank you for this info. I spose the filter gives the enhancement of the HA so it has more punch to the image then once its done then I’m assuming.

Thanks!

Dale

Elmiko

May 28, 2021

Just process it normally. If you like natural looking stars you can take a couple of hours capturing with a Uvir filter, then blend both stacks in PixInsight. There are several methods to do this. I would suggest checking out Visible DarkCA…Shawn Nielsen on utube. He shows a method on how to do it using PixInsight.

Tom Gray

May 28, 2021

Dale, you’ll definitely find it helpful on emission targets, and it does let you image under bright skies, but not without some noise. You should find it really enhances the Ha and OIII in your one shot colour images. Have fun.

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Dale Penkala

Topic starter

May 28, 2021

Elmiko:
Just process it normally. If you like natural looking stars you can take a couple of hours capturing with a Uvir filter, then blend both stacks in PixInsight. There are several methods to do this. I would suggest checking out Visible DarkCA...Shawn Nielsen on utube. He shows a method on how to do it using PixInsight.

Thanks for the reply Elmiko, I use Gimp so probably won’t work but I’ll check it out and maybe it will give me an idea how to do something like that.

Dale

Dale Penkala

Topic starter

May 28, 2021

Tom Gray:
Dale, you’ll definitely find it helpful on emission targets, and it does let you image under bright skies, but not without some noise. You should find it really enhances the Ha and OIII in your one shot colour images. Have fun.

Great! Thanks Tom, I’m looking forward to trying it now for sure. I’ll post once I get some images with this filter that I’m happy with!

Dale

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Dale Penkala

Topic starter

May 30, 2021 · Edited: May 30, 2021

Ok so I got the opportunity to try out this filter on a more suitable target, the Pelican Nebula. And from all the comments here on this thread, YES I LIKE THE FILTER FOR THE CORRECT OBJECTS!

Thanks so much!

Dale.

While I know that this isn't the greatest image here is a 2.33hr image. Unfortunately the moon come up the last 1hr 20min's of the image so its noisy and has some banding going on. Don't know how to eliminate the banding other then collecting more data and combining the data.

IC 5070 - The Pelican Nebula

Dale Penkala

Topic starter

May 30, 2021

OK don't know why the image isn't showing as I've attached it twice now.

Sorry

Tom Gray

May 30, 2021

It’s showing in post Dale, very nice, with good colour and detail. It may be my vision, bit is there a slight green gradient in stars..

Dale Penkala

Topic starter

May 30, 2021

Tom Gray:
It’s showing in post Dale, very nice, with good colour and detail. It may be my vision, bit is there a slight green gradient in stars..

I see it now, thanks Tom

Elmiko

May 30, 2021

Turned out great Dale!

Dale Penkala

Topic starter

May 30, 2021 · Edited: May 30, 2021

Elmiko:
Turned out great Dale!

Thanks Elmiko, I’m not familiar with dithering and how you would apply it.

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Observatório Astrográfico do Boqueirão

May 31, 2021 · Edited: May 31, 2021

Contact this guy: (https://www.astrobin.com/users/joaoporto/)
He's the man for the job

He even does Hubble Pallete (as he says) with the L-Enhance using SII+Ha+OIII in a color CMOS

Funny part over, the Iris nebula is a broadband target like galaxies, so the L-Enhance is not the best suited filter on using it, despite of some of the info (very dimm info) pass by the OIII and HBeta part of the filter. You'll have better results with a L-Pro filter or a color RGB with Luminance filter.
Another problem is to shoot with the filter through moonlight. The moonlight cross almost all light spectrum which means that even using that filter, most of the light will enter in the CMOS by the OIII and HBeta lines. My advice of this is to avoid moon at all costs. I have the same filter, and my best results using it is when I don't have moon in the nightsky and on emittion nebula targets like the M8, M16, NGC7000, M27, etc.

Regards,

Cesar

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Dale Penkala

Topic starter

May 31, 2021

Contact this guy: (https://www.astrobin.com/users/joaoporto/)
He's the man for the job
He even does Hubble Pallete (as he says) with the L-Enhance using SII+Ha+OIII in a color CMOS

Funny part over, the Iris nebula is a broadband target like galaxies, so the L-Enhance is not the best suited filter on using it, despite of some of the info (very dimm info) pass by the OIII and HBeta part of the filter. You'll have better results with a L-Pro filter or a color RGB with Luminance filter.
Another problem is to shoot with the filter through moonlight. The moonlight cross almost all light spectrum which means that even using that filter, most of the light will enter in the CMOS by the OIII and HBeta lines. My advice of this is to avoid moon at all costs. I have the same filter, and my best results using it is when I don't have moon in the nightsky and on emittion nebula targets like the M8, M16, NGC7000, M27, etc.

Regards,

Cesar

Hello Cesar
Thanks so much for your comments! I have learned a lot about this filter thru this thread that is for sure.

Am I understanding you correctly that the L-Pro filter is a better filter for the Galaxy and reflection nebula type/broadband objects???

I know its always better to image without the moon but I’m always looking for a way to image with the moon in the sky as its a pretty prominent object that seems to always be in the sky when we don’t want it! LOL

Dale

Observatório Astrográfico do Boqueirão

May 31, 2021 · Edited: May 31, 2021

Yeps, Dale.. the L-Pro fights a little bit light pollution in broadband targets and is better suited for blocking the artifical lights in sodium and mercury.
I use is brother the IDAS LPS D2 and I bough exactly for that, broadband targets for my color CMOS.
The L-Pro is for broadbrand targets fighting some light pollution in the city and suburban areas. But even with it, as well the other Optolong filter, they can't fight moonlight.. Actually for moonlight I don't know any filter who can do it to be honest. I'm doing a scientific paper about it, and those are the conclusions that I'm getting it. The moonlight cross about everything in the visible spectrum amost to the infrared and UV light

Regards,

Cesar

P.S. Did you check the "expert" above?

Dale Penkala

Topic starter

May 31, 2021

Yeps, Dale.. the L-Pro fights a little bit light pollution in broadband targets and is better suited for blocking the artifical lights in sodium and mercury.
I use is brother the IDAS LPS D2 and I bough exactly for that, broadband targets for my color CMOS.
The L-Pro is for broadbrand targets fighting some light pollution in the city and suburban areas. But even with it, as well the other Optolong filter, they can't fight moonlight.. Actually for moonlight I don't know any filter who can do it to be honest. I'm doing a scientific paper about it, and those are the conclusions that I'm getting it. The moonlight cross about everything in the visible spectrum amost to the infrared and UV light

Regards,

Cesar

P.S. Did you check the "expert" above?

Thanks for the info and explanation Cesar. May have to give one a try.

No I haven’t yet but will check him out!

Thanks!
Dale