M27's halo is not an extremely faint object, but still difficult for city skies.
I gathered data in four short (without astronomic dawn) nights in June.
One of those nights had an 80% full moon in addition to the city lights. I only took Ha in that night.
Taken from Berlin with a Celestron RASA on a G11 mount, ASI 1600MM cool camera, 133x2 min Halpha and 124x2 min OIII.
I have attached a full HD crop, the full field can be found at
http://ccd-astronomy.de/temp12/M27colourgut.jpg
Stefan