Optolong H-Alpha 3nm 2″ Narrowband Filter

The Optolong H-Alpha 3nm 2″ is a narrowband filter designed specifically for astrophotography to capture images of celestial objects that emit light at the hydrogen-alpha (H-alpha) wavelength. It is one of Optolong’s specialized filters, optimized for isolating the H-alpha emission line with a very narrow passband of 3 nanometers (3nm). This narrow passband allows only a small range of wavelengths centered around the H-alpha line (656.3 nanometers) to pass through the filter, effectively blocking out most other wavelengths of light.