This is a four-panel mosaic of the Lagoon Nebula region imaged using 12-nm filters centered on the spectral lines of Hydrogen alpha, Sulfur II and Oxygen III. All the data were recorded in the outer suburbs of Sydney, Australia. It took me 1 million years to merge all of the panels
because of light pollution gradients.
https://flic.kr/p/SR6n4a
https://flic.kr/p/RKTRv5
https://flic.kr/p/Ssynqf
Technical details:
Televue Nagler Petzval 127is at f/4.2, Astronomik 12-nm SII, Ha and OIII filters, QSI683wsg camera cooled to -20 Celsius. All sub-frames at 2x2 binning.
I would recommend using 1x1 binning whenever possible. However, I used 2x2 binning to record about 350 sub-frames at 10 minutes each to create a four-panel mosaic. 2x2 binning helped to reduce the total integration time.