Bicolour Images from OSC data (How does this look?)

[Stuf1978]

I've been wanting to create bicolour images from dual band OSC data for quite a while and tutorials on how to do this are pretty thin on the ground unless it involves PixInsight or to a lesser extent APP, both of which I don't have. There doesn't seem to be much out there for us using Photoshop for image processing. However, I did stumble over this tutorial that uses Siril to extract the Ha and O3 signals from OSC data when using dual narrow band filters and then tweaking the colour balance in Photoshop:

 

I'm pretty familiar with Siril as I sometimes us it for photometric colour calibration and the autostretch algorithm is really rather good.  However, with this tutorial I found the results pretty underwhelming and there wasn't much distinction between the colours. This may have been due to my workflow but I tried it several times and didn't like the results I got. So in the end I though why not use the extracted Ha and O3 channels from Siril and combine these into a HOO palette within Photoshop. I followed the above tutorial up until the point he moves into Ps.

I then opened a new workbook in Photoshop and assigned the extracted Ha data to red and the extracted O3 data to green and blue and then processed my image as normal. I did find that the stars ended up a bit funky so I removed them with Starnet++ and then re-added them after I reprocessed the stack just for the stars. 

So here is the finished image using this method for the first time. I may go back and try it all again and see if I can get the colour balance a little better as I think some of the reds are a bit harsh so it could may be do with toning down: Anyway please let me know what you think and which image you prefer?

Acquisition details: WO Redcat 51, ZWO ASI 294MC Pro, Optolong L-eXtreme, 72 x 300 second lights with darks, flats and dark flats, from a Bortle 8 zone.

I've included the normally processed data as a comparison.

If anyone would be interested in a full tutorial please let me know and I'll put one together

Also if anyone has any hints or tricks in processing OSC data in this way please let me know. 

Cheers,

Stu

 

Edited September 13, 2021 by Stuf1978