This is a project that was executed over three years and all started with me not knowing what to image when I was first starting out with astrophotography. Back in 2020 I got a RedCat and a Sky-Watcher Star Adventurer star tracker. After spending a few months hitting the "highlights" of bright objects, I couldn't figure out what to image next (this was back when I was doing a different object each night), so I thought: "hey, there's a lot of fun stuff in Cygnus, why don't I just make a mosaic of it?" Little did I know what that would entail, especially this being my first mosaic I imaged...


I just kept adding new frames each time I could, and after upgrading to a Stellarvue SVX 102T scope, I decided to just keep the RedCat running on this project. Everything was done completely manually, no mosaic planning software, just eyeballing it in Stellarium and then plate solving each night. Over the years, the mount and guiding setup were upgraded, so some frames are unguided, some with a dedicated guider (ZWO mini scope), and some with an OAG. The Sky-Watcher "mount" was also upgraded to a CGX.


Finally some time in late 2022, early 2023, I decided to call it quits, mostly because I wanted to upgrade the camera I was using and didn’t feel like adding a new camera to the already complex mosaic.From a technical perspective, I can’t stand how rough this image look with all the stacking artifacts, inconsistent colors and background luminosity, etc. But I had to stop somewhere, especially considering that it takes AstroPixelProcessor (APP) about a week to form the full mosaic when using LNC (local normalization correction), and actually can’t even render the full resolution and downscales it by a factor of 60%!! Then I needed to crop and further decrease the resolution to get it to fit on Astrobin.
If you want to see the original FITS, it can be accessed here: https://www.dropbox.com/s/awysburvvpz9hst/No_CSC_LNC_2_4_try_more_subs_0.5_scale_with_CSC_hole_fill-RGB-session_1-csc.fits?dl=0
The full resolution starless version can be found here: https://www.dropbox.com/s/e506gjd77uzm0kh/No_CSC_LNC_2_4_try_more_subs_0.5_scale_with_CSC_hole_fill-RGB-session_1-St-Starless.tiff?dl=0
And a full resolution (well, as full as APP could do, 60% of full resolution) PNG of the final version can be found here: https://www.dropbox.com/scl/fi/i136o3ta1018d5ff8m7y9/Full-rez-final-2.png?rlkey=vc98dtizpz0c4s4iuspx7dao9&dl=0

I recommend taking a look at the full resolution images, since I had to compress the heck out of them to get them to display on astrobin. The PNG is 1.3 GB, the starless TIFF is 2.1GB, while the AstroBin version is just 143MB. I also had to down-scale the resolution of the AstroBin version due to the issue with total number of pixels needing to be smaller.

Computationally, each integration was done on a machine with 36 cores and 128GB RAM and took about 1.2TB of intermediate disk usage. Depending on the settings, this could take either a day, or an entire week. Through tedious trial and error, I ended up integrating the full mosaic about 20 times or so. I feel sorry for my poor SSDs!

In total, there are 98 frames in this mosaic (though some of them overlap very significantly). I spent roughly 3-4 hours of imaging time on each frame. Individual subs were 90 seconds each and a total of 12,015 such subs were used in this mosaic. Interestingly, this worked out to a total of just over 300 hours of total integration time. I quite lucked out with 2020-2022 central PA weather having an abnormally large number of clear nights.

There are a bunch of interesting little things in this image, with many of them on my “to do” list for follow up imaging with my bigger scope. These are annotated in one of the revisions and include a couple of things that will certainly require follow up since I can’t seem to find out what they are in Stellarium (and before I go digging too deeply, I want to make sure they aren’t artifacts).

So this is as finished as it’s going to be, and I thought I’d share it, warts (and interesting stuff!) and all.