Astronomik H-beta visual SC Rear Cell (2" / 24TPI) (SKU: 10214050 / 8h00ar)

Astronomik H-beta visual SC Rear Cell 2" / 24 TPI (Astronomik, SKU: 10214050) is a visual filter for objects emitting light in the H-beta line. It is primarily intended for larger telescopes and specialized observation of faint hydrogen nebulae such as the Horsehead Nebula.

Key features

• selection of the H-beta emission line
• background suppression when observing faint hydrogen regions
• intended for visual observation with a sufficiently large aperture
• mounts on a telescope rear port with a 2" / 24 TPI SC thread
• durable coatings resistant to scratches and moisture

Included items

• filter, Astronomik H-beta visual SC Rear Cell 2" / 24 TPI
• protective filter box

Technical specifications

• manufacturer: Astronomik
• manufacturer SKU: 10214050
• type: H-beta visual-observation filter
• transmission range: 480–492 nm
• passband width (FWHM): 12 nm
• typical transmission at 486 nm: 97%
• recommended aperture: approximately 200 mm or larger; 250–300 mm for the Horsehead Nebula
• recommended focal-ratio range: f/4–f/6
• mount: rear SC / SCT connection
• thread: 2" / 24 TPI, nominal diameter 50.8 mm
• glass thickness: 1 mm
• parfocality: with standard Astronomik filters using 1 mm glass
• country of manufacture: Germany

With a suitable telescope, the filter helps distinguish very faint nebulae emitting in H-beta.