OIII 8nm Narrow Band filters isolate the doublet emission of doubly ionized Oxygen. After ionized hydrogen, this is the next most common emission when imaging nebulae. Doublet emission occurs at 495.9 and 500.7 nm.
- Parfocal for systems f/4.0 or slower
- Transmitted wavefront better than 0.25 waves/inch
- Parallelism: less than 30 arcsec
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