Astronomik UHC 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 these ultra-thin filters, we are currently doing only a selection of filters, which are mostly used for widefield imaging. If you require a XT filter not listed below, please drop us a line.

The Astronomik UHC is THE filter for visual observing.

You will enjoy using your Astronomik UHC filter because you will see more stars and more details in deep-sky-objects compared to using filters from all other manufacturers.

The Astronomik UHC (Ultra High Contrast) filter allows the transmission of nearly 100% of the radiation from both O-III and the H beta lines. Though the second window for the H-alpha-line is not intended for visual observing, it is important, if the filter is used with an electronic device. All annoying, scattered light from other wavelength sources, including local artificial light pollution, is reliably filtered out. With this strong blocking of the sky background an unexpected wealth of detail becomes visible for gas nebulae and planetary nebulae.

Main use

Astronomik UHC filters astounding high light transmission brings better views of deep-sky-objects even to small telescopes! The high transmission of our optical glass filters means that enough light is available to allow successful visual observations with telescopes beginning at 2" (50mm) aperture. Our Astronomik filters are optimized for use with telescope focal length f / ratios of f/4 to f/15. Transmission losses and chromatic distortions, which arise with other filters, only occur with Astronomik filters when extremely bright aperture ratios of 1:2 and more come into play. Another major advantage of our Astronomik UHC filter is the high optical quality of the filter glass. When using Astronomik UHC filters you will quickly notice the same needle-sharp stars which you are familiar with from your astronomical instrument without any filter!

Suitability

• Visual observation (dark skies): Very good, for telescopes of all apertures and high exit pupil
• Visual observation (urban skies): Very good, for telescops from 100 mm aperture
• Film photography: Reasonable, but very long exposure time
• CCD photography: Good, when used with an additional IR-block-filter
• DSLR photography (original): Good, colour balance shifted but contrast enhanced
• DSLR photography (astro modified): Very 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): Good, if light pollution is a big problem

Technical Data

• typ. 97% transmission at 486nm (H-beta)
• typ. 97% transmission at 496nm (OIII)
• typ. 97% transmission at 501nm (OIII)
• typ. 97% transmission at 656nm (H alpha)
• optimum position of transmission for telescopes with focal ratios from f/10 to f/3,5
• Entire Blocking of annoying wavelengths
• Ideal All-round Deep Sky filter even for small telescopes
• Not sensitive to humidity or aging
• Scratch-resistant!
• Excellent carrier material. The optical performance of your telescope is not reduced by the filter in any way.
• 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