Astronomik UHC-E Filter XT Clip-Filter EOS APS-C

Do you own a Canon EOS digital camera for astro-imaging? Then you have surely encountered the following problems:

• Large filters for large camera lens objectives are very expensive
• If you place a filter holder between your camera body and lens you loose the ability to focus to infinity
• For very fast (low f/ number) telescopes like the Vixen R200SS or the Takahashi Epsilon astrograph, a filter drawer or a filter wheel cannot be used since the distance to the corrector lenses would be changed.
• With long exposure times your cameras sensor chip is exposed to more dust

With the Astronomik Clip-Filter System you can take care of all of these problems at once!

The patented Astronomik Clip-Filter System is black anodized aluminum and laser-cut on state-of-the-art modern machines. It can be inserted within seconds directly into the EOS camera body. There are no changes necessary and all lens functions (focus, screen, image stabilization) remain functional!

Almost all Canon system lenses (with the exception of the EF-S series) and all M42 and T2 lens adapters, can be used with the Astronomik Clip-Filter System. The Clip-Filter System also acts as an outstanding dust shield, which prevents the possibility of dust settling on the sensor during long time exposure (The MC-Clear filter does not have a filter effect and only acts as a dust shield.)

List of compatible Canon EOS cameras:

Important: Not suitable are cameras offered before 2003 and all varieties of the Canon EOS 1D and EOS M.

The new Astronomik XT filters are designed to give you widefield-images with beautiful crisp and sharp stars right to the edge of the field.

Our Astronomik Clip filters are a popular and very well known tool among astrophotographers in the whole world. Sadly image quality was limited when using them with very short focal lengths to take widefield images: Even if the normal Astronomik filters are made of 1mm thick glas only, some wideangle lenses showed aberrations in the edge of the field of view when used with Clip-filters.

The new Astronomik XT filters are coated on an ultra-thin substrate with a thickness of 0.3mm only! Due to that the residual aberations are minimized and stars are crisp and sharp right into the corner of the image.

This extremely thin substrate is polished to the highest standards, free of internal strain and stress and suitable even for the most advanced imaging applications.

The XT filters are produced in the same way as the normal Astronomik filters: 100% scratch resistant, not sensitive to moisture or high humidity and no-ageing. Due to this the XT filters will have the same performance today and in many years in the future. To emphazise this you get a 10 year warranty on our filters!

Please note: Not all Astronomik filters are available as XT filters: Due to the huge amount of work to produce thes

The Astronomik UHC-E filter is our budget filter for deep-sky observation of emission nebulae and comets under light polluted skies. Its 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 Jupiters 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

• typ. 94% transmission at 486nm (H-beta)
• typ. 95% transmission at 496nm (OIII)
• typ. 95% transmission at 501nm (OIII)
• typ. 94% transmission at 656nm (H alpha)
• transmission 465nm to 530nm and above 645nm
• Full width at half maximum 45nm
• 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
• Since 2008 we do ship filters with a completely new design. Any kind of halo or strange reflection is a matter of past