Narrowband filter for the OIII line at 500.1 nm
This filter is suitable for observation and photography of OIII regions from areas with artificial light pollution or areas with dark skies.
The OIII filter increases the contrast between certain types of astronomical objects (mainly supernova remnants and planetary nebulae) and the sky background. Due to its narrow half-width and high transmission in the OIII line range, it achieves a greater contrast increase than filters with a wider bandwidth. The range of application extends over an aperture ratio of 1:3 to 1:15 for telescopes from 6" (150 mm) aperture for observation at medium magnification and lenses and telescopes of all diameters for astrophotography.
Mode of action
The filter completely blocks the emission lines of low- and high-pressure lamps (mercury (Hg) and sodium (Na)) and the lines of the airglow. The two OIII lines can pass through the filter with very high transmission.
