I accidentally stumbled on how to make mosaics while trying to combine some data in Astro Pixel Processor. I had been taking images in Cygnus around the star Sadr and was trying to pull out some more detail when I realized that what I had done was make a mosaic! Since I had done it with two images, I decided to take some more panels and see what I could come up with:
Since I hadn’t planned to do it from the start, my panel structure was off so I had to take one more panel then I would have needed to if I had planned it out ahead of time.
Total integration time is 21 hours and 20 minutes. This makes it my image with the longest integration time. Integration for each panel:
Propeller Nebula – 48 x 300s
Crescent & Tulip Nebulae – 48 x 300s
Region near Farawis – 48 x 300s
Tulip Nebula – 39 x 300s
Sadr & Crescent Nebula – 73 x 300s (two sessions, one from June of last year and one from June of this year.
I used Stellarium to help figure out my framing and center point for capturing the panels. I captured each panel on a different night and stacked them in DeepSkyStacker. Mosaic was combined using Astro Pixel Processor and I saved the combination as an unstretched linear image. I processed the linear image using Photoshop. Processing consisted of color balance, stretching by levels and curves, noise removal using NoiseXterminator and various Astrophotography Tools Actions. Since I shot from Bortle 8, I had some weird gradients (my neighbor also had their backyard light on for two of the nights). Also, since I hadn’t planned to do a mosaic from the start, my framing was very inefficient. For my next mosaic, I will actually plan it better and probably use Teloscopius to figure out my framing. I tried several different processing techniques, first using a stretched image from Astro Pixel Processor, as well as using Siril to stretch the individual stacks before combining them in APP. In the end, linear combination and processing was the best!
Visit the upload on Astrobin.com for full annotation and details
Equipment & Statistics
Radian Raptor 61
Canon EOS Ra
Optolong L-eNhanced Filter
Sky Watcher EQ6-R Pro
ZWO 30mm f4 MiniScope (guide)
ZWO asi224mc (guide)
27 x 300s (800 ISO)
Dark, flat, bias and dark flats calibration frames
Bortle 8 – Providence, RI