Astronomik - H-Beta Filter - SC Thread

The Astronomik H-beta is a filter for visual observation of hydrogen nebulae, 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 Nebula with telescopes of 10" - 12" reaches the realm of possibility.

Main use:

The optimal focal ratio for the use of the filter is f/4.5 to f/6. The range of application extends from f/3.5 to f/15. Transmission losses and chromatic distortions, which arise with other filters, are only apparent with the Astronomik filters when extremely fast focal ratios of f/3 and faster 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" (20 cm) 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.

Suitability:

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 and CMOS photography: Good, when used with an additional IR-blocking filter

DSLR photography (original): Very good, but only suitable for a few objects

DSLR photography (astro modified): Very good, but only suitable for a few objects

DSLR photography (MC modified): Good, when used with an additional IR-blocking filter

Webcam / Video (Planets): Unsuitable

Webcam / Video (Deep Sky): Unsuitable

Technical Data:

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

Parfocal with other Astronomik filters

Glass thickness: 1 mm

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

 

Safety informations: PDF Download