Available in 1.25", 2", EOS-C, EOS-FF, NIKON-FF
The Optolong UHC (Ultra High Contrast) broadband filter is designed to improve the visibility of deep sky objects such as emission nebulae and supernova remnants. The UHC filter can be used for both visual observations as well as astrophotography.
It rejects the typical wavelength associated to artificial light and it is highly transparent in the main emission nebula lines: OIII (496nm and 500nm), H-beta (486nm), NII (654nm and 658nm), H-alpha (656nm) and SII (672nm).
For astronomy cameras it needs to be used in combination with an IR/UC cut filter. Alternatively it can be used the CLS-CCD filter that cuts off the infrared and ultraviolet wavelengths. In DSLR's the IR/UV filter is embedded in the camera so the standard UHC filter is sufficient.
Light pollution filters do not eliminate the effects of light pollution or increase the object’s brightness, instead they increase the contrast between objects and the night sky.
Maximum transmission of the main nebula emission lines at OIII (496nm and 500nm), H-beta (486nm), NII (654nm and 658nm), H-alpha (656nm) as well as SII (672nm).
Blocks artificial light
Cuts through mercury vapour, high and low pressure sodium vapour lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere.
All Optolong filters feature multi-layer anti-reflection coatings.
Schott optical glass
2mm thick glass made of Schott monolithic optical substrate (non-glued), in ultra-thin, CNC-machined, anodized filter cell (1mm for clip on DSLR series).