SVBONY SV220 Telescope Filter, SII & OIII 7nm Dual-Band 2" Nebula Filter, High Transmission Cut-Off Depth OD5, Enhancing Imaging Contrast, Reduce Light Pollution for Astrophotography

SV220 2'' Dual Narrow bandwidth SII/O-III 7nm narrowband filter properly designed for astrophotography both in light polluted Allows for imaging in bright man-made light pollution and moonlit conditions; Useful for imaging emission nebulae; planetary nebulae and supernova remnants Designed to sharply cut off the inference of artificial light from sodium vapor or mercury vapor street lights and other unwanted disturbance like sky glow Note Recommended for optical systems from f/4