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[Sticky] Combining R, G, B with Ha & OIII data using an Optolong L-eNhance filter
Excuse this simplistic question, but this procedure implies you need (1) a set of image files with no filter, and then (2) a second set of image files collected thrpugh an L-Enhance or L-extreme filter ?? Please advise.
Is there another workflow for L- images only?
You can follow the instructions just for the L images basically, that would be a very similar workflow.
The difference is that Ha - OIII Color will create a color image with R represented by the Ha signal and G and B by the OIII signal. It is similar to, but slightly different from, the default Adaptive Airy Disk. By using Ha - OIII separate Ha (or OIII) the Ha (or OIII) signal gets extracted producing a mono image.
I am struggling to get a Ha, OIII or mono image following the process described in the workflow from page 1:
1. The result does not differ, if I select Ha-OIII extract Ha, Ha-OIII extract OIII or Ha-OIII mono algorithm in the first step:
2. Then, I load (calibrated) light frames shot with a dual-narrowband filter (Optolong L-eXtreme) and the ZWO ASI294MC Pro
3. Clicking integrate will produce a color image, that looks the same regardless which algorithm I selected in Tab 0:
I have tried it with APP 1.082 and the current APP 1.083 beta.
Do you have any advice, where I do make a mistake?
@rudibarani Hi Philip, if in a first step you select Ha-OIII extract Ha and integrate and then in a second step Ha-OIII extract OIII and integrate again, you'll get one mono image with the Ha signal and one mono image with the OIII signal. Then you can go to tab 9 and use "combine RGB" selecting either HOO 1 or HOO 2 to combine the mono Ha and OIII images. The way you described combines the raw images using the Adaptive Airy Disc algorithm in tab 0 which produces a default RGB image ignoring the fact that you were using a dual band filter when you shot the images. Of course it is possible to go that way too but then you'd better select the Ha-OIII Color algorithm in tab 0 to get better separation of the Ha and OIII signal.
thanks for the quick reply. I did select "Ha-OIII extract Ha" and "Ha-OIII extract OIII" in Tab 0 and thought that each integration would lead to a mono image that I would then combine later. Currently, I do end up getting a color image from each integration (Ha-OIII extract Ha/OIII/mono) without combining them.
I tried some additional combinations and found that Ha-OIII extract Ha/OIII/mono works fine when I put in "raw" light-frames + MD/MB/MF.
If I put in calibrated light-frames (as I did so far), I do get a color-composite despite selecting Ha-OIII extract Ha/OIII/mono. Is this intended behavior or just a misunderstanding on my side?
@rudibarani Hi Philip, that is a very good question. I'll ask Mabula and will get back to you with an answer as soon as possible.
@rudibarani Hi Philip, using those algorithms with calibrated data still should work as long as the data has not been debayered. Can you please check that that is the case?
thanks a lot for this suggestion. I had calibrated the subs initially to align the channels and get rid of a slight chromatic aberration. I thought this would be an improved storage format for my data and that I am not limited in its future use.
If I deselect this option during calibration, the resulting subs can be used to extract Ha, OIII etc. without a problem:
Maybe it would be possible to add a note if the input data seems to have been debayered and cannot be used with the selected algorithm, e.g. extract Ha.
@rudibarani When you split the channels via the extract Ha/OIII algorithms and then combine them again, the channels will be aligned when you combine them again. And aligning of the color channels can only be done with debayered data. Still, you have a point that this can be calirfied better. I'll pass on your suggestion to Mabula.