Astronomik 50 mm Square Unmounted UHC Filter
The Astronomik UHC filter is for visual deep-sky observation and some imaging applications.. It lets almost 100% of the radiation from both O-III lines and the H-beta line pass through. A second bandpass for the H-alpha line ensures that this radiation also reaches the eye, and scattered light from other wavelength ranges is also filtered out. Due to the strong reduction of the sky background, gas and planetary nebulas are visible with an unexpected abundance of detail. Because of the high transmission, the UHC filter provides enough light to successfully observe deep-sky objects with smaller telescopes.
Astronomik UHC filters are optimized for use with focal ratios of f/4 to f/15. Unlike other filters on the market, loss of transmission and color displacement with the Astronomik filter occurs only on telescopes with extremely fast focal ratios of f/3 on up. Compared to the UHC filters sold by other manufacturers, the Astronomik UHC filter shows you more stars and more details in nebulas, and because of the high quality of the glass, you will see stars as small pinpoints.
Astronomik filters are in a class by themselves when compared to other filters made by Japanese and US manufacturers. The coatings are completely sealed and insensitive to moisture. They do not change with the years, but keep their transmission characteristics indefinitely. The coatings are so hard that is it not possible to scratch them by mistake. You would have to rub them with sandpaper to get even the finest of scratches! Due to these outstanding characteristics, Astronomik gives them a 5 year guarantee. Each filter will be sent in a useful protective case.
Astronomik 50 mm Square UHC Filter Features...
- Transmission of nearly 100% of O-III and H-beta
- Transmission of 96% of H alpha
- Entire blocking of annoying wavelengths
- Ideal all-round Deep Sky filter even for small telescopes
- Not sensitive to humidity or aging
- 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
- 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
Visual, Webcam & Imaging 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
Astronomik Product Number: UHC-50SQ