Astronomik UHC-E

The Astronomik UHC-E filter is our budget filter for deep-sky observation of emission nebulae and comets under light polluted skies. It’s particularly suitable for small ’scopes.

The UHC-E Filter increases contrast of emission nebulae and comets and blocks the light of typical streetlights as well as airglow. It is best suited for telescopes up to 5" / 125mm.

Main use

The Astronomik UHC-E filter provides a FWHM of 45nm and blocks the light of typical streetlights (e.g. sodium and mercury vapour) as well as airglow. Thus it increases contrast between your target and the night sky. The contrast enhancement is less than that of the Astronomik UHC filter, but at the same time the transmitted amount of starlight is greater. It's therefore better suited to smaller telescopes. As the UHC-E filter passes a spectral line of Carbon (due to the higher FWHM) it opens up the possibility of comet observation.

Other uses

Observation of Jupiter’s clouds.
Easier resolution of Double Stars.
Photography under light-polluted skies with DSLRs and other cameras.

Alternatives

If you use a telescope with an aperture larger than 5", we suggest the use of our standard UHC-filter because of its greater contrast enhancement capabilities. If you use a telescope larger than 8", you can try our OIII filter for even better results when observing specific nebulae.

Suitability

Visual observation (dark skies): Reasonable, an UHC filter is more suitable
Visual observation (urban skies): Good, for telescopes up to 125 mm aperture and medium exit pupil
Film photography: Good, but very long exposure times
CCD photography: Good, when used with an additional IR-block-filter
DSLR photography (original): Good, colour balance is near perfect
DSLR photography (astro modified): Good, colour balance is near 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 a big problem

Technical Data

Maximum transmission of 94%
Full width at half maximum 45nm
Transmission range 480nm to 525nm and 645nm+
Parfocal with other Astronomik filters
Glass thickness: 1mm
Completely resistant against high humidity, scratches and aging effects
Diffraction limited, the filter will not reduce the optical performance of your telescope!
Astronomik filters are delivered in a high-quality, long lasting, filter box