The Svbony SV220 Duo-Band (2") narrow-band filter makes the work of astrophotographers using colour cameras in light-polluted urban environments easier. It passes light through only two very narrow wavelengths while blocking other wavelengths.
The Svbony SV220 Duo-Band (2") narrow-band filter has 90% and 94% light transmission at Hα (656.3 nm) and OIII (500.7 nm) wavelengths, such as those emitted by emission nebulae.
The filter comes in a handy protective case. The filter is not recommended for telescopes with an f-ratio faster than f/4.
