Total integration time for this picture is quite large, but the conditions were not very good. I was shooting this between June 27th and July 14th on each clear(-ish) night, 13 different nights in total, 2-3 hours of imaging time per night on average. At the latitude of almost 57 degrees north, the Sun didn't ever set lower than 12 degrees below the horizon at the time of shooting. As H-alpha is much more tolerant to twilight glow than Oiii, first 4 nights were dedicated to Ha, and then the rest of the time I concentrated on Oiii until I was satisfied with the results.
I think the absolute minimum threshold for acquiring somewhat usable data with H-alpha filter is when the Sun is about 8.5 degrees below the horizon, and about 10.5 degrees for Oiii filter. On the plus side, you don't really care about light pollution and the Moon being 100% illuminated when you are shooting in such conditions
All things considered, I am very pleased with the results, and for me it is somewhat unexpected.
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