cheap nebula filter

The Astronomik UHC-E filter is the economical filter for deep sky observation of emission nebulae and comets under light polluted skies. It is particularly suitable for small telescopes.

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

The Astronomik UHC-E filter provides an FWHM of 45nm and blocks light from typical streetlights (eg sodium and mercury vapor) as well as airglow. Thus, it increases the 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 amount of transmitted starlight is greater. It is therefore better suited to small telescopes. When the UHC-E filter passes a carbon spectral line (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 are using a telescope with an aperture larger than 5", we suggest using our standard UHC filter due to its superior contrast enhancement capabilities. If you are using a telescope larger than 8", you can try our OIII filter for even better results when observing specific nebulae.

Informations:

• Visual observation (dark sky): Reasonable, a UHC filter is more suitable
• Visual observation (urban sky): 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 additional IR block filter
• DSLR photography (original): good, color balance is almost perfect
• DSLR photography (astro modified): good, color balance is almost perfect
• DSLR photography (modified MC): good, when used with additional IR block filter
• Webcam / video (planets): not suitable
• Webcam / Video (Deep Sky): Very good, if light pollution is a big problem

Technical data

• typ. 94% transmission at 486 nm (H-beta)
• typ. 95% transmission at 496 nm (OIII)
• typ. 95% transmission at 501 nm (OIII)
• typ. 94% transmission at 656 nm (H alpha)
• transmission from 465 nm to 530 nm and over 645 nm
• Full width at half maximum 45 nm
• Parfocal with other Astronomik filters
• Glass thickness: 1mm
• Fully resistant to high humidity, scratches and the effects of aging
• Diffraction limited, the filter will not reduce the optical performance of your telescope!
• Astronomik filters come in a high quality, durable filter housing
• Since 2008 we have been shipping filters with an all new design. Any type of strang
• halo or reflection is a matter of the past