English: Emission nebulae in the constellations Cepheus and Cassiopeia seen by the Northern Sky Narrowband Survey. In this false color image, doubly ionized oxygen ([OIII] at 500.7 nm) is mapped to red, ionized hydrogen (Hα at 656.3 nm) is mapped to green and singly ionized sulfur ([SII] at 671.7 nm and 673.0 nm) is mapped to blue. The brightest stars are added to visualize the regions contaminated by strong continuum light. (Aside from that, the image does not contain continuum light.)

The field of view is 33° × 22°. Equatorial center coordinates are RA=23h8m and DEC=65°. North is up.

The red nebula at the top of the image and the large blue filaments to the right of the center are supernova remnants. Most of the other emission nebulae, shown in various colors (see the image annotations), belong to the Orion Arm of the Milky Way and lie roughly 2,800 to 3,600 light-years away.