Zhumell 1.25" High Performance Ultra High Contrast UHC Filter

This UHC, or Ultra High Contrast, filter decreases the effects of light pollution caused by natural and artificial sources. With this filter, the background sky appears darker in the eyepiece, increasing the visibility of your favorite deep-sky objects. This filters out specific wavelengths of light to create high contrast and to make nebulae clearer and more visible, where normally, we may not be able to see it with our eyes alone.

Skyglow, which is caused by neutral oxygen in the atmosphere, as well as light from high and low-pressure sodium vapor lights and mercury vapor lamps, are suppressed significantly, which means you can view or image from areas of heavy light pollution.

Optolong’s UHC filter lets desirable wavelengths pass at a peak transmission of emission lines at OIII, H-Beta, NII, H-Alpha, and SII. 

This Zhumell 1.25” UHC Filter is made with multi-coated glass to ensure scratch resistance and stability on the central wavelength or CWL. Each filter cell is made of lightweight, strong metal and is CNC machined, sand-blasted, black anodized, and then laser engraved.