The beautiful California Nebula in Perseus is very large in our sky -- about 2.5° long, or nearly the length of five full moons. But it is very, very dim. Viewing it in binoculars or a telescope can be very challenging and a dark site is essential. It is a very popular target among astrophotographers and it is easy to see why.
Viewing California Nebula
Mid-November through February
In Perseus, find Mirfak and Algol. Find Menkib. Look less than 1° (1 finger-width) from Menkib in the direction of Adid Australis.
From a dark site with no moon, view stars scattered throughout the nebula. With a larger telescope it may be possible to view some nebulosity especially with a special H-Beta filter on the eyepiece to block out all but the light from the nebula. Low power is best since it is so large.