Astronomik H-Beta Filters
The Astronomik H-beta is a filter for visual observation, in particular with instruments of larger aperture.
It lets the light of the H-beta emission line pass nearly unhindered and blocks the remaining spectral range to the extent that the eye is dark adapted. By the use of the Astronomik H-beta filter, the contrast is increased so strongly, that even the observation of the Horse Head Nebulae with telescopes of 10" - 12" reaches the realm of the possible.
The optimal aperture ratio for the use of the filter is 1:4,5 to 1:6. The range of application extends from 1:3.5 to 1:15. Transmission losses and chromatic distortions, which arise with other filters, are only apparent with the Astronomik filters when extremely fast aperture ratios of 1:3 and higher are used. The Astronomik H-beta filter will allow you to view large objects, in the whole field of view of the eyepiece, even when using wide-angle eyepieces - not only in the center of the eyepiece. This filter should be used on telescopes with a diameter of 8" (20cm) or larger. Smaller instruments do not gather enough light for meaningful and satisfying astronomical work. Due to the high optical quality of the Astronomik H-beta filter substrate you will see the same needle-sharp stars as you would from your regular telescope.
- Visual observation (dark skies): Very good, but only suitable for a few objects
- Visual observation (urban skies): Unsuitable
- Film photography: It depends, very long exposure time
- CCD photography: Good, when used with an additional IR-block-filter
- DSLR photography (original): Verry good, but only suitable for a few objects
- DSLR photography (astro modified): Verry good, but only suitable for a few objects
- DSLR photography (MC modified): Good, when used with an additional IR-block-filter
- Webcam / Video (Planets): Unsuitable
- Webcam / Video (Deep Sky): Unsuitable
- Transmission of nearly 100% of the H-beta line
- complete blocking of all disturbing wavelengths
- Main operational use: Hydrogen Nebulae
- No moisture (humidity) sensitivity, no aging, and totally scratch-proof
- Excellent carrier material - substrate is optically polished. The optical performance (resolution & contrast) of your telescope is not reduced in any way by the filter.
- 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