
Description
SII filters isolate the spectral emission of singly ionized sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, at 671.6 and 673.1 nm. This filter also separates sulfur emission from H-alpha emission (656.3nm). Chroma’s f/3.0 filters are designed to minimize spectral shift and hold their shape better in an f/3.0 beam.

Buy risk-free: When it’s time to trade up you’ll get the most value for your used gear.