OSC Optolong l-eNhance colour

Questions and answers about processing in StarTools and how to accomplish certain tasks.
Melty
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Joined: Fri Dec 22, 2017 1:18 pm

OSC Optolong l-eNhance colour

Post by Melty »

Hi,

I've recently started using the above mentioned filter in my imaging, and was wondering what's the best way to go about using the Colour module, if at all.

Currently, I process as I normally would any other OSC image, but I skip out the colour balance step altogether, as by it's very nature, there isn't a full gamut of colour to work with from the outset (with it being dual-narrowband). My brief experiments with it result in skewed star colours and a rather washed out image.

Is this a mistake, as my images so far have plenty of Ha, but I'm not seeing much Oiii as yet? I know this varies from target to target, but I just work like to have an idea of the best workflow.

Cheers all
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admin
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Re: OSC Optolong l-eNhance colour

Post by admin »

Hi,

There are a few ways you can go about this.
In all cases, you will definitely want to color balance, as the nature of most objects (e.g. nebulae) is that the Ha emissions are much stronger than the OIII/Hb emissions. This usually means O-III/Hb's contribution to color needs to be boosted quite a bit.

A popular way to process duo-band filtered data, is to extract the two bands and process them as a HOO composite;
  • In the Compose module, load your OSC dataset as red. StarTools will extract the red channel only. Keep and save this as your Ha data.
  • In the Compose module once more, load your OSC dataset as green and blue. StarTools will extract the green and blue channels only. Set 'Luminance, Color mode' to 'L + Synthetic L from RGB, Mono'. Keep and save this as your O-III/Hb data.
  • To process your data as a popular HOO composite, in the Compose module once more, load your Ha data as red, O-III/Hb as green, O-III/Hb as blue. Set Luminance, Color mode to 'L + Synthetic L from RGB, RGB'. Set 'Green Total Exposure' or 'Blue Total Exposure' to 0 (for synthetic luminance signal purposes, we only want to count the O-III/Hb data once, not twice).
You can now process this dataset as normal (you will notice some subtle differences in how some modules behave while Compose mode is on).

Hope this helps!
Ivo Jager
StarTools creator and astronomy enthusiast
Melty
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Re: OSC Optolong l-eNhance colour

Post by Melty »

Awesome, Ivo!

I'll take a note and try this when I get chance.

:obscene-drinkingcheers:
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admin
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Re: OSC Optolong l-eNhance colour

Post by admin »

Hi,

I just wanted to add that I've added some specific Duoband functionality to the Color module in the latest 1.6 alpha. This lets you choose from different channel assignments (and thus color schemes) without having to reprocess/reload the data.

Clear skies!
Ivo Jager
StarTools creator and astronomy enthusiast
Melty
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Re: OSC Optolong l-eNhance colour

Post by Melty »

admin wrote:Hi,

I just wanted to add that I've added some specific Duoband functionality to the Color module in the latest 1.6 alpha. This lets you choose from different channel assignments (and thus color schemes) without having to reprocess/reload the data.

Clear skies!
Just reprocessed my previous Duo-NB data, and the new version works like a charm.

Great work as ever, Ivo!
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Re: OSC Optolong l-eNhance colour

Post by admin »

Melty wrote:
admin wrote:Hi,

I just wanted to add that I've added some specific Duoband functionality to the Color module in the latest 1.6 alpha. This lets you choose from different channel assignments (and thus color schemes) without having to reprocess/reload the data.

Clear skies!
Just reprocessed my previous Duo-NB data, and the new version works like a charm.

Great work as ever, Ivo!
That's great to hear as I don't have too many Duoband datasets to test with here.
Ivo Jager
StarTools creator and astronomy enthusiast
rchoski
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Re: OSC Optolong l-eNhance colour

Post by rchoski »

Hi all,

I am having trouble getting this to work for me.

Data was captured with a Canon 600D (modded). 135mm lens. Optolong l-eNhance filter. 300s exposures. N. Am. nebula.

Stacked in DSS. No white balancing selected.

When I process the fts file as a normal image, there is colour. Pink/red nebula etc.

I have tried to follow the above tips to process as HOO, but get completely stuck. Sure I am doing something very stupid. Basically, whatever I try, the end result is in monochrome when I get to the colour module. With 1.6 alpha I can get lots of red if I choose the 600d identity, but don't think it is working as intended.

Not sure if I am going wrong with the selections in Compose or maybe when exiting compose and selecting the nature of the data?

Fts file is hopefully available below
https://www.dropbox.com/s/gn5413hgkkiqd ... s.fts?dl=0

Thanks for any help
Richard
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Re: OSC Optolong l-eNhance colour

Post by admin »

Hi Richard,

It may be the case that you are choosing the second option (e.g indicating that the dataset is Linear, straight from an OSC/DSLR with Bayer matrix and not white balanced), while you just made a composite in the Compose module (which means that the dataset is not straight from an OSC/DSLR any more).

If this is the case, then know that this has caught out a couple of other people, so I'll be changing some things in 1.6.
If this is not the case, do let me know.
Ivo Jager
StarTools creator and astronomy enthusiast
rchoski
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Re: OSC Optolong l-eNhance colour

Post by rchoski »

Hi Ivo

Choosing the correct option fixed the monochrome problematic you suggested

Now to get practising my processing!

Thanks very much.

Richard
Chunkles
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Re: OSC Optolong l-eNhance colour

Post by Chunkles »

Hi,

Here is some image data from my new ASI533 using the L-enhance filter:

https://drive.google.com/file/d/1uM6WMf ... sp=sharing

It was from 2 hours of integration in a heavily light-polluted (Bortle 8) zone. Stacked with Flats and Darks. I know I need more integration time (as always). I'd like to be able to play with the new Duoband settings, but really at a loss on workflow as I've never done any NB before (this is first image since my DSLR days). I've only done a quick processing the normal way and got this below. If anyone wants to take a shot and provide their workflow, I'd appreciate it. I'm especially interested in how to use things like the Hubble palette om these emission nebula with this filter to get those blues and yellows.
Image
Thanks for your help!
-Scott
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