SVBONY SV220 dual narrowband H-Alpha/O-III 7nm narrowband filters are specially designed for astrophotography in light-polluted environments, allowing imaging under bright artificial light pollution and moonlight conditions to capture color images without using multiple filter combinations. Images are most useful with single-use color cameras; can be used for imaging emission nebulae, planetary nebulae, and supernova remnants; high transmittance and sharp cutoff can greatly enhance contrast, showing the most detailed information about deep sky objects; designed to drastically cut off sodium Artificial light interference from vapor or mercury vapor street lights and other unwanted interference (e.g. sky glow); Dual Band Narrow Band Filters are not suitable for visual observation and are not designed for imaging or observing the sun.SV240 2" Multi-Narrowband Galaxy & Nebula filter NIR near-infrared light pollution filter is a new galaxy and nebula filter intended for shooting not only nebulae, but also galaxies by the use of the transmittance around the near infrared region.IT can be used to image most deep sky objects, including galaxies, reflection nebulae, emission nebula, and star clusters from a Bortle 1 location to Bortle 8; passing near-infrared region is for shooting deep sky objects that cannot be imaged with other filters without NIR transmission.SV220 is suitable for photographing emission nebulae and supernova remnants; SV240 is suitable for photographing galaxies and reflection nebulae. With this filter set, you can better meet a variety of shooting needs.