Astronomik H-Beta Filter - 1.25" Round Mounted
Astronomik 1.25" H-Beta Visual Filter
The optimal aperture ratio for the use of the filter is 1:4 to 1:6. 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" (200mm) 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.
Astronomik 1.25" H-Beta Visual Filter Features
- 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
Questions & AnswersAsk a Question
what is the FWHM of this filter (12nM)?
The FWHM is around 13-15nm based on the bandpass graph that Astronomik publishes for this filter.