* Astronomy

The narrowband UHC filter, like the O-III filter, isolates the two doubly ionised oxygen lines (496 and 501nm) in addition to the hydrogen-beta line (486nm) emitted by planetary and most emission nebulae. This filter permits superb views of objects like the Orion, Lagoon, Swan and other extended nebulae. It performs well in smaller aperture instruments owing to its greater light transmission than the O-III, yet still suppresses light pollution well. The UHC filter is the best all-around dark-sky nebula filter. Available in two sizes, threaded to fit either standard 1.25" or 2" astronomical eyepieces. Supplied with storage case.

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SkyWatcher Ultra High Contrast Filter

UHC Filter 1.25"      ~ £40.00
UHC Filter 2"      ~ £70.00

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This Ultra-High Contrast filter is basically a nebula filter, that also suppresses light pollution and skyglow. The filter will enhance planetary and lunar views. It should be noted that galaxies and faint objects will not show any improvements.
The filter can be used with all  telescope apertures.