Chroma Technology 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 Technology SII filters are available in the following filter sizes:

• 1.25″ Mounted
• 2″ Mounted
• 31mm Unmounted
• 36mm Unmounted
• 50mm Unmounted
• 50x50mm Square Unmounted

Optical Density Data:

All transmission and blocking (OD) data are actual, measured spectra of representative production lots. Spectra varies slightly from lot to lot. Optical density values in excess of 6 may appear noisy because such evaluations push the resolution limit of low light level measurements.