Astronomik H-alpha 6 nm MaxFR Clip-Filter EOS R XL (Astronomik, SKU: 10212221) is a narrowband filter for imaging hydrogen nebulae and HII regions in the H-alpha line. Selective transmission increases the contrast of the nebular signal by reducing unwanted background light at both dark and light-polluted sites. The Clip-Filter EOS R XL version is designed to fit inside a compatible camera body.
• narrow 6 nm passband that increases nebula-to-background contrast
• blocking of unwanted out-of-band radiation, including UV and IR
• use with CMOS and CCD cameras to record a separate emission-line channel
• narrower passband than 12 nm filters suppresses background and starlight more strongly
• the filter must not be used for solar observation
• installation and removal of the Clip-Filter without modifying the camera body or using additional tools
• coatings: MaxFR, designed for fast optical systems; also usable with slower instruments
• optically polished glass and durable coatings resistant to scratches and humidity
• one Astronomik filter in the specified version, SKU: 10212221
• protective storage box
• manufacturer: Astronomik
• manufacturer SKU: 10212221
• filter type: H-alpha narrowband
• emission line: 656 nm
• full width at half maximum (FWHM): 6 nm
• guaranteed transmission for the H-alpha line at 656 nm: over 90%
• typical transmission for the H-alpha line at 656 nm: 93%
• out-of-band blocking: from UV to IR
• coatings: Astronomik MaxFR
• fast-optics range without significant transmission loss: f/2.2–f/6
• transmission relative to maximum at f/2: approximately 90%
• mounting: Clip-Filter EOS R XL
• compatible Canon EOS cameras: R, Ra, RP, R3, R5, R5 Mark II, R6, R6 Mark II, R8, and R7 and R10
• not compatible with Canon EOS R50, R50 V or R100
• incompatible Canon RF lenses: 14 mm f/1.4 L VCM; 28 mm f/2.8 STM; 35 mm f/1.8 IS Macro STM; 85 mm f/1.2L USM
• not compatible with Canon Extender RF 1.4× and 2× teleconverters
• storage: in the supplied box between sessions; the manufacturer advises against leaving the filter permanently inside the camera
• glass thickness: 1 mm
• parfocality: with Astronomik filters with 1 mm glass thickness
• country of manufacture: Germany
The H-alpha filter records a selected component of nebular emission as a separate channel for further processing or a multiband composite.
