Astronomik UHC SC Rear Cell 2" / 24 TPI (Astronomik, SKU: 10210050) is a nebula filter that passes the principal hydrogen and oxygen emission lines while suppressing background light. It helps reveal structure in emission and planetary nebulae by selecting wavelengths rather than increasing the brightness of the object itself.
When imaging with an infrared-sensitive camera, an additional IR-blocking filter may be needed if this function is not already provided by the camera. This filter does not have the response of a version with additional infrared blocking.
• transmission of H-beta, OIII and H-alpha emission lines
• selective suppression of light outside the useful nebular bands
• suitable for observing and photographing nebulae
• mounts on a telescope rear port with a 2" / 24 TPI SC thread
• durable coatings resistant to scratches and moisture
• filter, Astronomik UHC SC Rear Cell 2" / 24 TPI
• protective filter box
• manufacturer: Astronomik
• manufacturer SKU: 10210050
• type: UHC nebula filter
• transmission range: 480–505 nm and above 645 nm
• main passband width (FWHM): 25 nm
• typical transmission at 486, 496, 501 and 656 nm: 95%
• recommended focal-ratio range: f/3–f/15
• 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
Selective transmission helps separate the nebular signal from the sky background.
