Sh2-155 is a diffuse nebula in the constellation Cepheus, within a larger nebula complex containing emission, reflection, and dark nebulosity. It is widely known as the Cave Nebula. Sh2 designation because it’s part of the Sharpless Catalog (1959) of 312 HII regions. About 2400 light years from Earth and a stellar nursery.
Narrowband filters really do cut through the murky, light polluted skies of Edinburgh so well. Obviously false colour, has to be for narrowband, but can’t decide which is the best so two different tone mappings: SII Ha OIII -> RGB and Ha OIII SII
First real narrowband image. Strange reflections of the primary, secondary and spider in Ha and OIII images, as well as flats. Mappings were OHS and HOS. SII didn’t add much to either image but object is strong in Ha and OIII.
B33 in IC343
250mm f4.8 Newtonian MPCC Guided PHD2
Atik 460EX Baader Ha, OIII, SII filters
15x200s 2×2 each filter 15 each of darks, flats, bias
Nebulosity and Photoshop Colour mapping: OHS: OIII, Ha, SII HOS: Ha, OIII, SII.