Optolong UHC Filter

The UHC filter is one of the most popular and widely used filters to combat light pollution.

Usually used for visual observations, the UHC (Ultra High Crontrast) filter has the classic Gaussian cut that allows light pollution from sodium and mercury lamps

The big brother of the UHC filter is the L-PRO filter, which is much more efficient and has a multiband cut-off.

Main use and performance

Suitable for observing low emission nebulae in the lines of 656 nm H-alpha, 496 nm and 500 nm OIII, 672 nm SII and 486 nm H-beta in moonlight or heavy pollution conditions luminous with 95% transmission!

The UHC filter does not eliminate the effects of light pollution and does not increase the brightness of the photographed object, but rather increases the contrast between the nebula and the night sky, making image processing easier.

This UHC filter is designed to be used screwed on the eyepieces, in the filter wheels, in the filter holder drawers or directly on the CLIP model cameras.
Technical characteristics

Technical data

• Schott substrate material
• Thickness 2.0mm (1.25"/2")
• Thickness 1.0 mm (Clip series)

Spectral curve

•     The main emission lines of nebulae
•     Hb of 486.1 nm
•     OIII 495.9nm and 500.7nm
•     672 nm SII
•     Ha 656.3 nm

    The main emission lines of artificial light pollution
    Hg is 435.8 nm, 546.1 nm, 577 nm and 578.1 nm
    Na is 598 nm, 589.6 nm, 615.4 nm and 616.1 nm