Red and Blue Nebulas in Perseus
This is the California Nebula (aka NGC 1499) in Perseus, a classic red emission nebula emitting mostly at the red wavelength of hydrogen-alpha light but also with a strong hydrogen-beta emission line in the blue-green part of the spectrum.
By contrast, below is the small blue reflection nebula known only as IC 348, a cloud of dust surrounding hot blue stars and reflecting their light. But the region also contains some dim red emission nebulosity.
Also throughout the field are patches of yellow-brown dust that form obscuring dark nebulas. The main dark nebulas are Barnard 5 (above IC 348) and Barnard 4 below.
This is a stack of 8 x 8 minute unfiltered exposures at ISO 800 blended with a stack of 9 x 15-minute exposures through an Optolong L-Enhance narrowband filter, to bring out the emission nebulas. All were with the Canon EOS Ra camera through the William Optics RedCat 51mm astrograph at f/4.9, equipped with the Starizona filter drawer. Autoguiding was with the Lacerta MGEN3 stand-alone autoguider on the Astro-Physics Mach 1 mount. All stacking, alignment and blending was with Photoshop. Luminosity masks applied with Lumenzia to do selective curves adjustments to various tonal ranges.
Shot from home November 15, 2020.