Triangulum is yet another member of our local group of galaxies, about three million light years away and is the third largest behind our own Milky Way and Andromeda, one of the distant permanent objects that can be seen with just your naked eye under the right conditions.

Imaging this galaxy ended up being a complicated process. I collected all the data that went into one of the final images over a couple of years. I had earlier collected the luminance and narrowband data on my Takahashi FS128N with the mono QHY163M camera in 2017 but I decided to redo this one in OSC with the colour QHY247C camera and the FC100DF tube. I then went about creating an image that combined all of the collected data by first creating a synthetic luminance channel which combined the luminance data from both the colour and mono cameras, then created a new LRGB image combining this with the separated red, blue and green channels and then added the Ha, O3, and S2 data to this image at a 80:20 ratio using PixelMath.

The great but sometimes frustrating aspect of astrophotography is that there are so many ways to produce a "final" image. I find the variant without the narrowband data and just only with mono (L) data just as aesthetically pleasing (and it is interesting to observe the differences). In addition I tried out different weightings for the channel combinations and also different approaches for combination including PixInsight's NBRGB combination script. At this point, this is just one of the few choices among what I considered aesthetically pleasing and also reasonably accurate in terms of representing the data. Short of combining all the respective channels, I ended up doing little post processing for now.

Normally I've been tending towards combining RGB channels in linear form and then processing them further but this time I created the final "look" of each channel as I wanted it and just combined them which locks you in with earlier choices. This can be both good and bad, since as I write above, there are many branch points and they largely seem to produce interesting results. To this end, I also put up the synthetic LRGB only image (containing all the luminance and OSC data) and also the complete luminance image for comparison. As always, thanks for looking!