Player One SII 7 nm 1.25" S-series narrowband filter (SKU: SII7-125) is designed for imaging nebulae in the emission band of singly ionised sulphur (S II). It allows a separate sulphur channel to be recorded for use in multicolour narrowband compositions.

Key features

• selective recording of nebular structures emitting in the S II band
• suppression of background light outside the passband
• ability to combine S II data with exposures taken through other filters

Set contents

• mounted Player One SII 7 nm 1.25" S-series filter

Technical specifications

• nominal size: 1.25"
• bandwidth (FWHM): 7 ± 0.5 nm
• transmission: approximately 90%
• substrate: optical glass
• coatings: multilayer composite
• glass thickness: 2.0 ± 0.03 mm
• surface accuracy: λ/4 on both sides
• out-of-band blocking: OD3
• near-infrared blocking range: 700–1100 nm
• filter cell thread: M28.5 × 0.6
• filter cell height: 5 mm body + 2.5 mm thread, 7.5 mm total