The ZWO Narrowband Deep Sky Filters are an excellent choice for astrophotographers aiming to capture the highest contrast CCD images in the H-alpha, O-III, or S-II wavelengths. These filters exhibit excellent light transmission properties within the selected wavelength range while completely "cutting off" light at other "unwanted" wavelengths.
The filters' superior glass material and craftsmanship promise excellent contrast and image sharpness. The coatings are applied using state-of-the-art equipment, ensuring the ideal transmission range. The anti-reflective coatings contribute to outstanding image formation, and additionally, the surfaces have been treated to make the 2 mm glass material scratch-resistant.
All three filters have a maximum light transmission capability of over 80%, with the H-Alpha filter peaking at a wavelength of 656 nm, the O-III filter at 500 nm, and the S-II filter in the 672 nm range. They primarily aid in the photographic capture of nebulae, supernova remnants, etc., that emit in these radiation ranges.