The Astronomik OIII 12nm Clip-Filter EOS R APS-C (Astronomik, SKU: 10220092 / 8h11ve) is a narrowband emission filter designed for Canon EOS R APS-C mirrorless cameras. This model was developed for imaging nebulae showing oxygen emission in the OIII 496 nm and 501 nm lines, both under light-polluted skies and at dark observing sites. Thanks to its 12 nm Full Width Half Maximum bandwidth, the filter effectively increases the contrast between the object and the sky background, while still remaining a good choice in systems where a larger number of visible guide stars is important. The version with MFR coating is intended for use with conventional optical systems and can be used in instruments with focal ratios from f/3 to f/15 without visible loss of performance.
• narrowband OIII filter for Canon EOS R APS-C cameras
• designed for imaging oxygen-emission nebulae
• 12 nm Full Width Half Maximum bandwidth
• high image contrast thanks to effective suppression of the sky background
• blocking of unwanted light outside the OIII lines from UV to IR
• MFR coating for use with conventional optical systems
• can be used in instruments with focal ratios from f/3 to f/15
• high transmission at the main OIII 501 nm line
• good visibility of guide stars compared to narrower filters
• parfocal with other Astronomik filters
• Astronomik OIII 12nm Clip-Filter EOS R APS-C
• filter storage box
• manufacturer: Astronomik
• product name: OIII 12nm Clip-Filter EOS R APS-C
• SKU: 10220092 / 8h11ve
• intended use: imaging oxygen-emission nebulae
• camera compatibility: Canon EOS R7, Canon EOS R10, Canon EOS R50, Canon EOS R50 V, Canon EOS R100
• non-compatible lenses: Canon RF 14mm f/1.4 L VCM, Canon RF 28mm F2.8 STM, Canon RF 35mm F1.8 IS Macro STM, Canon RF 85mm F1.2L USM, Canon Extender RF 2x, Canon Extender RF 1.4x
• guaranteed transmission: more than 90% at the main OIII 501 nm line
• typical transmission: 95% at the main OIII line
• FWHM: 12 nm
• coating: Astronomik MFR
• recommended focal ratio range: from f/3 to f/15
• glass thickness: 1 mm
• parfocality: yes, with other Astronomik filters
• optical quality: diffraction-limited
• coating resistance: highly resistant to scratches, humidity, and aging
• country of manufacture: Germany
