I had a bit of time to experiment with an H-alpha filter at home. Conditions are limiting astro-imaging as my balcony faces south. Living in the northern outskirts of a city, all the sky visible is significantly affected by city lights. This night, the sky was somewhat OK, reaching up to 18.7 to 19.5 mag/arcsecĀ².
Using narrow band filters, like an H-alpha filter, the majority of the city lights may be cut away. This image (not perfectly focussed) shows, what is possible. It is a result of 12x240s, captured at ISO800 with my modified Sony A6000…