Astronomik UHC-E M Filters

The Astronomik UHC-E filter is a budget-friendly option for deep-sky observation of emission nebulae and comets, especially under light-polluted skies. It is particularly suitable for smaller telescopes up to 5" (125mm).

Main Use

The Astronomik UHC-E filter offers a full width at half maximum (FWHM) of 45nm, effectively blocking light from typical streetlights (sodium and mercury vapor) and airglow. This enhances the contrast between your target and the night sky. While the contrast enhancement is less than that of the Astronomik UHC filter, it allows more starlight to pass through, making it ideal for smaller telescopes. The UHC-E filter also passes a spectral line of Carbon, opening up the possibility for comet observation.

Other Uses

• Observation of Jupiter’s clouds
• Enhanced resolution of double stars
• Photography under light-polluted skies with DSLRs and other cameras

Alternatives

For telescopes with apertures larger than 5", we recommend our standard UHC filter for greater contrast enhancement. For those using telescopes larger than 8", consider our O_III filter for improved results when observing specific nebulae.

Suitability

• Visual observation (dark skies): Reasonable; UHC filter is more suitable
• Visual observation (urban skies): Good for telescopes up to 125mm aperture and medium exit pupil
• Film photography: Good, but requires very long exposure times
• CCD photography: Good when paired with an additional IR-block filter
• DSLR photography (original): Good; color balance is nearly perfect
• DSLR photography (astro modified): Good; color balance is nearly perfect
• DSLR photography (MC modified): Good when used with an additional IR-block filter
• Webcam / Video (Planets): Unsuitable
• Webcam / Video (Deep Sky): Very good if light pollution is significant

Technical Data

• Typical transmission of 94% at 486nm (H-beta)
• Typical transmission of 95% at 496nm (O_III)
• Typical transmission of 95% at 501nm (O_III)
• Typical transmission of 94% at 656nm (H-alpha)
• Transmission from 465nm to 530nm and above 645nm
• Full width at half maximum: 45nm
• Parfocal with other Astronomik filters
• Glass thickness: 1mm
• Completely resistant to high humidity, scratches, and aging effects
• Diffraction-limited; the filter will not reduce your telescope's optical performance
• Astronomik filters are delivered in a high-quality, long-lasting filter box
• Since 2008, we ship filters with a new design that eliminates halos and strange reflections