Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when imaging nebulae.

Chroma Technology OIII 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.