Compose module using duochannel data

[U308041]

I saw some info on loading duo channel data from my Optolong L enhance filtered data into compose module to process them as HOO composite.. The first step was to load your dataset as RED and save as Ha. The step I don't understand is " Load the same dataset as green and blue. Set Luminance, Color mode to L +Synthetic L from RGB Mono. I load the blue and green one at a time . Keep and save this as your O-iii/Hb data." keep Then I have two choices, Linear and non linear and not sure what is correct at this point considering what I have just done. Also am I backing out of Star tools and restarting the program with compose and importing my data I just saved as Ha to red and the OiiiHb as green and blue. ? It is rather confusing . I am rather new at this and appreciate any help.

[happy-kat]

You don't need to close startolls between each Compose use.
The data is still linear you just split the channels and saved.

[admin]

If you're using 1.7, there are now composite modes available specifically for duo/tri/quad-band filters like yours.

Load your dataset a red, again as green, again as blue. StarTools will extract the channels automatically.
Then set "Luminance, Color" to "L + Synth L From R(2xG)B, R(GB)(GB) (Bi-Color from OSC/DSLR)".
It's a long description, but it does what it say on the tin; your luminance will be created by adding R, 2xG and B together, while your coloring will be red, green+blue and green+blue for red, green, blue respectively. This the the standard/popular HOO palette. You can remap it in the color module to something else your liking of course.

Hope this helps!

[firebrand18]

Following this thread with interest as also use L-Enhance with QHY168C OSC. Up till now, been doing Ivo's earlier recommended process of duo-band filtered data by extracting the two bands and processing them as an HOO composite.
• In Compose, load OSC dataset as Red to extract the red channel only and save as Ha data.

• In Compose again, load OSC dataset as Green AND Blue to extract the green and blue channels only. Set 'Luminance, Color mode' to 'L + Synthetic L from RGB, Mono'. Keep and save as O-III/Hb data.

• To process as an HOO composite, in Compose, load 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, only count the O-III/Hb data once, not twice).

I am now using 1.7.434 alpha and loving the enhanced features being added (Super Structure module is superb); StarTools is my go-to image processing software for over a year and will remain so.

Per Ivo's new process below, looks like the above is no longer necessary; just one-shot flow in Compose module and load as Linear; my question is: do we now set the total exposures for r+g+b equally for each (e.g. 4 hours 10min total integration) or still set green or blue to zero like before?

Keep up the great work; can't wait to see what's next!

[admin]

Keep up the great work; can't wait to see what's next!

Thank you! Your kind comments mean a lot!

my question is: do we now set the total exposures for r+g+b equally for each (e.g. 4 hours 10min total integration) or still set green or blue to zero like before?

When importing a DSLR/OSC dataset, you can just keep the exposure times as they are; the Compose module will do the proper weighting (I may even disable them when the dataset is from a DLSR/OSC). You don't even have to set them as long as they are all the same for red, green and blue. The Compose module just uses them to do the proper weighting, so it doesn't really matter whether they are all set to 1 hour or 1 minute, the ratios between them are the same. I hope that makes sense.

[firebrand18]

Yes it does and love the new functionality as also saves disk space; no more storing 100mb files each for Ha and OIII along with the main image stack.

Cheers.

[firebrand18]

I forgot to ask; in the Wipe module, do you have to (or recommend) to always use the NrwBand preset with data coming from a filter like the L-Enhance or can use Basic depending on how the image looks when toggling Luminance and Color?

Amount of detail/color will be different between the two presets and sometimes Basic looks better than NrwBand, sometimes not; just wondering if there is a negative impact choosing Basic in this case, where NrwBand will yield better results as you flow through the small/medium detail modules and especially at the end in the color module.

Clear skies.

[admin]

I forgot to ask; in the Wipe module, do you have to (or recommend) to always use the NrwBand preset with data coming from a filter like the L-Enhance or can use Basic depending on how the image looks when toggling Luminance and Color?

Amount of detail/color will be different between the two presets and sometimes Basic looks better than NrwBand, sometimes not; just wondering if there is a negative impact choosing Basic in this case, where NrwBand will yield better results as you flow through the small/medium detail modules and especially at the end in the color module.

The narrowband preset is just a very "gentle" preset; gradients are usually not as apparent in narrowband data as things that cause them (chiefly light pollution domes and moonlight) are usually filtered out or not present. Being as gentle as possible is always preferable, so, really, that's only the main difference there.

Of course, being gentle that may not always be appropriate for one reason or another, even in "professionally" acquired data.

Hope that makes sense/helps!

[firebrand18]

Yes, makes sense. Thanks for the prompt replies!

Cheers.