Player One HSO 7 nm 2" S-series narrowband filter set (SKU: HSO2 SET) includes three mounted filters for imaging nebulae: Hα, S II and O III. They allow the emission of hydrogen, singly ionised sulphur and doubly ionised oxygen to be recorded separately.

Data collected through the individual filters with a monochrome camera can be combined into multicolour narrowband compositions. Among other possibilities, the set allows images to be created using the SHO palette, in which the S II channel is assigned to red, Hα to green and O III to blue.

Key features

• separate recording of nebular structures emitting in the Hα, S II and O III bands
• suppression of background light outside the passbands
• ability to create narrowband compositions, including images using the SHO palette

Set contents

• mounted Hα 7 nm 2" filter (SKU: HA7-2)
• mounted S II 7 nm 2" filter (SKU: SII7-2)
• mounted O III 7 nm 2" filter (SKU: OIII7-2)

Technical specifications

• number of filters in the set: 3
• nominal size: 2"
• bandwidth of each filter (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: M48 × 0.75
• filter cell height: 5 mm body + 2.5 mm thread, 7.5 mm total