I compared a couple of large faint nebulae with a 12" Dob a few nights back.
NGC 1499 (the California nebula) seemed to be fainter than IC 2177 (the Seagull nebula) but that was probably because 1499 was lower in the sky.
Only the bright parts of both nebulae were visible and a UHC filter was best on IC 2177.
The attached wikisky.org images are 225' by 225' and north is up. The nebula transit before midnight DST (1499) and before 3am this month.
I did not take them. They are from the DSS2.
The images are easy to make, go to wikisky.org, type in the object name, set the zoom level (about half way) and click on the camera icon.