SVBONY SV220 dual narrowband H-Alpha/O-III 7nm narrowband 1.25'' filter is 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. Please note that the SV220 is not well suited for fast telescopes, some users have reported that dual-band OSC filters paired with RASA can cause band shifts, thus clipping HA data.UHC filters or light pollution reduction filters are designed to selectively reduce the transmission of certain wavelengths of light;especially those produced by artificial light.It helps with finding the little planetary nebulae because it dims everything but the nebula.Due to its ability to produce exceptionally sharp and clear images;this UHC filter is considered one of the most popular astronomy accessories;it can be used not only for celestial observations but also for astrophotography.SV226 filter drawer adopts integrated CNC molding and anti-light leaking design. It can also use 1.25" & 2" specifications on the market. Easier to install and pull out, but also provides effective installation protection, no need to worry about damage to the filter.The filter drawer comes with the M42-M48 adapter to resolve the thread compatibility issue. The interface can compatible with astronomical cameras of different specifications.