OSC Optolong l-eNhance colour

[Stefan B]

Great that you were able to reproduce the result! You're right about the stars. I am usually pretty lazy on that and revisit the color module immediately after the first run of the color module. I use a star mask so only the stars are manipulated in the second run and I just set the saturation to 0. All color of the stars is gone and they are grey/white. Another option would be to rebalance only the stars in the mask (or to use an inverted star mask in the first run so that stars don't get affected in the first place?). Or to replace the duo NB stars with broadband RGB stars. But you would need an additional imaging session without or with UV/IR cut / broadband LP filter for that.

It appears to me that M 16 isn't especially rich in OIII so the shift is pretty harsh if one wants to get a decent OIII coloring. It's easier with the North America Nebula. One can get nice blues without unbalancing so much:

Here, a similar workflow like for your M 16 has been applied.

I also tried to get a image with rather "natural/true" colors with the legacy preset and some tweaks with this result:

NGC700,0, 2021-06-18, 46x5min, Legacy.jpg (619.4 KiB) Viewed 5261 times

Just in case you're interested in different color palettes, maybe you can also try on your M 16.

Best regards
Stefan

[Stefan B]

PS. When you have tried your starnet approach I'd be interested in the results and the workflow. I've never used this...

[Carles]

I've recently got an L-eXtreme and was able to try it a bit last night with Lagoon and triffid nebula
, taking 35minutes with L-eXtreme and tried to merge it with 1h40min I had with L-Pro filter.

L-extreme TESTS2.jpg (705.73 KiB) Viewed 5185 times

Upper left is L-pro only.
Lower left is Compose mode - L-extreme as Luminance and Lpro as RGB
Upper right is Lpro as RGB and L-extreme as NBAccent
Lower Right is full charge

• Splitted RGB from L-pro and also OIII and Halpha from L-Extreme
  merged R+Halpha, Blue+OIII
  opened Compose again and loaded RGB-Lpro as Luminance, then R+ha, G, B+Oiii and L-extreme as NBAccent.

maybe that's over do it a bit, but I think I like this last one the better.

Haven't tried false colour or bicolour...so far, what you guys think? : )

Clear skies!

Carles.

[Mike in Rancho]

Well that's full charged alrighty!

I haven't tried these yet, they were a bit low and in the wrong place when I wanted to, but aren't the Lagoon and Trifid bright enough that normal RGB acquisition will pick up all if not most? I think the Veil or Crescent are usually good starter and test targets for new L-duo-filters.

[Stefan B]

Hi Carles,

great results! Personally, I prefer the version in the lower left (l-eXtreme as luminance and L-Pro as RGB). But that's really just a matter of taste.

But I am surprised that so much signal from Trifid's reflection nebulosity came through with the l-eXtreme. Did you have to bring this out seperately with the duo NB filter?

Regards
Stefan

[Carles]

Well that's full charged alrighty!

I haven't tried these yet, they were a bit low and in the wrong place when I wanted to, but aren't the Lagoon and Trifid bright enough that normal RGB acquisition will pick up all if not most? I think the Veil or Crescent are usually good starter and test targets for new L-duo-filters.

haha you're right, Mike! But when I first tried the filter the Lagoon and Trifid was OK, and the other areas of sky not so good.
two days ago got 2h35min on the Western Veil L-extreme only, processed as single file and then bicolor (as I remember)

Screenshot-1.jpg (246.41 KiB) Viewed 5157 times

Haven't got an RGB file yet for this field, but intent to

Carles

[Carles]

Hi Carles,

great results! Personally, I prefer the version in the lower left (l-eXtreme as luminance and L-Pro as RGB). But that's really just a matter of taste.

But I am surprised that so much signal from Trifid's reflection nebulosity came through with the l-eXtreme. Did you have to bring this out seperately with the duo NB filter?

Regards
Stefan

Hi Stefan!
thanks umm perhaps Lower left because of contrast? Saturation and color might be off.. my laptop's screen is not well calibrated (tried it many times...) and when I see it on my phone looks different. Stil, I prefer the "whole charge" one , as it preserves a lot of the reflection nebula from trifid as you mention
and about it,
this is the log part of the NBAccent and Color module modifications on this last (Lower Right)

Code: Select all

--- Color
Parameter [Bias Slider Mode] set to [Sliders Reduce Color Bias]
Parameter [Style] set to [Artistic, Not Detail Aware]
Parameter [LRGB Method Emulation] set to [RGB Ratio, CIELab Luminance Retention]
Parameter [Matrix] set to [Identity (OFF)]
Parameter [Dark Saturation] set to [Full]
Parameter [Bright Saturation] set to [4.4]
Parameter [Saturation Amount] set to [250 %]
Parameter [Blue Bias Reduce] set to [1.00]
Parameter [Green Bias Reduce] set to [1.86]
Parameter [Red Bias Reduce] set to [1.43]
Parameter [Mask Fuzz] set to [1.0 pixels]
Parameter [Cap Green] set to [99 %]
Parameter [Highlight Repair] set to [Off]
--- Visual Spectrum Narrowband Accent Compositing
Parameter [Response Simulation] set to [HII/Balmer Series (Red/Purple) + O-III (Teal)]
Parameter [Luminance Modify] set to [UNKNOWN]
Parameter [Detail Size] set to [0 pixels]
Parameter [Brightness Correlation] set to [Off]
Parameter [Strength] set to [1.00]
Parameter [Color Modify] set to [100 %]
Parameter [UNKNOWN] set to [69 %]
Parameter [UNKNOWN] set to [87 %]
Parameter [Band Balance] set to [72% / 28%]

I am guessing most of the blue comes from the Lpro/Broadband RGB , rather than l-extreme
this is screen shot of l-extreme data, only wiped and FilmDev

Screenshot-2.jpg (421 KiB) Viewed 5156 times

and this is after color->bicolor

Screenshot-4.jpg (367.89 KiB) Viewed 5156 times

So basically seems all H-alpha, a little of Oiii.

Regards

Carles.

[Stefan B]

Hi Carles,

I prefer the lower left version because of a bit more contrast and the color balance. But that's just my personal taste. In the lower right you get more of the surrounding blue nebulosity of the Trifid which is also great.

Thanks for the clarification on the reflection nebula in the l-extreme data.

Great veil, too, by the way!

In general the stars are relatively white. Did you use AutoDev or FilmDev? In my experience you get rather blue stars when using the l-enhance and AutoDev. I like the neutral color of the stars with using FilmDev but I prefer the DSO stretching of AutoDev. Is there a particular reason for using FilmDev for you?

Best regards
Stefan

[Carles]

Great veil, too, by the way!

In general the stars are relatively white. Did you use AutoDev or FilmDev? In my experience you get rather ..

Hi Stefan!

Do you mean in the Comparision? The stars aren't white really, it might be the compression of the picture to post here...
This is a crop of the "full charge one"
at least in my screen I can see various star colours..

NewComposite HaOIII split + NBAccent Crop.jpg (316.08 KiB) Viewed 5130 times

FilmDev vs AutoDev is kinda hard for me. Depending on the target, but also on the quality of the stack.
if for whatever reason I get a rather noisy stack, then FilmDev gives me an smoother image.. and also good color to start with. In order to not blow the stars too much (and try to mimick a little autodev in that regard) I increase the Gamma setting and adjust back the Digital Development.

But is true that AutoDev gives a better dynamic range..and smaller stars, but it is hard to work with and try not to get noise to pop up too much (talking about me, personally, I know other people are very profficient in AutoDev. ) On those cases, I really don't remember.
I always start my processing (after Wipe) with either AutoDev or FilmDev, and then do the other and compare (without exiting the module/applying) and see what i like more to go further.

After all it is all about personal taste ^^ . But for instance, my image of iris Nebula, was done with FilmDev. (just checked the log) and I am very happy with it. I've done many tests on that, and used AutoDev too,..but at the end, at least in this case, FilmDev worked better for me.
Extract from the log in that particular session

Code: Select all

--- Photographic Film Development Emulation
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.36]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [95.07 %]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [14.6 pixels]

Regards

Carles.

[Carles]

Besides,
I cropped the Lagoon from L-eXtreme and tried bicolor
First from Compose --> OSC... bicolor... didn't like the output :/

And after just "open" and then at Colour module- > bicolor> change increase bias and pushed up the Blue
and this came out quite interesting. (noisy and bluish background too but can be fixed)
Considering that's only 35min...and didn't follow a whole workflow, just basic to test colour.
it is a fun filter indeed

Carles.