Antlia 3 nm Sulfur II (SII) Pro narrowband filter 50x50 mm

Antlia 3 nm Sulfur II (SII) Pro 50 × 50 mm filter is a square unmounted filter for narrowband nebula imaging. It isolates sulfur emission, while its narrow 3 nm passband reduces the background contribution to the recorded signal.

Key features

• narrow passband for separate capture of an emission channel
• strong blocking outside the passband
• single non-cemented substrate with blackened edges

Included items

• unmounted Antlia 3 nm Sulfur II (SII) Pro 50 × 50 mm filter

Technical specifications

• manufacturer: Antlia
• dimensions: 50 × 50 mm
• thickness: 3.0 ± 0.05 mm
• material: Schott glass
• central wavelength according to the specification table: 672.4 nm
• full width at half maximum, FWHM: 3 nm
• peak transmission: > 88%
• out-of-band blocking: OD > 5 over 300–1000 nm
• surface quality: 60/40
• transmitted wavefront accuracy: λ/4 or better
• surface parallelism: < 30 arcseconds

A compatible holder or filter wheel for square filters allows this channel to be included in a multiband session with a monochrome camera.