UHC(Ultra High Contrast), UHC is also a broadband filter with an obvious effect on blocking city harmful lights. CLS filter blocks lights selectively, especially the mercury and sodium light from man-made lamps and the skyglow in nature. CLS filter lets the light from nebula highly transmit, it has a high transmittance at the region of OIII(496nm & 500nm), Hβ(486nm), NII(654nm &658nm), Ha(656nm)and SII(672nm). Our UHC with high-effectively improved the contrast of the nebula ,ensuring wonderful nebula details
OPTOLONG UHC filter astounding high light transmission brings better views of deep-sky-object even to small telescopes. The high transmission of our optical glass filters means that enough light is available to allow successful visual observations with telescopes beginning at 2" (50mm) aperture. Our filters are optimized for use with telescope focal length f / ratios of f/4 to f/15. Another major advantage of our UCH filter is the high optical quality of the filter glass. When using OPTOLONG UHC filter, you will quickly notice the same needle-sharp stars which you are familiar with from your astronomical instrument without any filter!