Baader ASSF 130 AstroSolar ClearWhite ND 5.1 (OD=5.1) 130 mm solar filter (Baader Planetarium, SKU: 2423040) is a front-aperture filter designed for safe visual observation and white-light solar photography using spotting scopes, amateur telescopes and telephoto lenses. Its 130 mm clear aperture enables the observation of photospheric details, including sunspots and the structures surrounding them, also at higher magnifications.

Key features

• AstroSolar® ClearWhite Safety Film with an optical density of OD 5.1
• reduces the intensity of sunlight approximately 125,000 times
• neutral, bright white image of the Sun without a pronounced blue or orange tint
• high image sharpness and contrast, enabling detailed observations of the photosphere
• double-sided metallized filter material mounted without tension
• aluminium cell with a reinforcing ring protecting the filter material
• construction limiting stress on the filter material caused by temperature changes
• adjustable centering screws enabling installation of the filter inside or outside the optical tube
• safety straps protecting the filter against accidental slipping
• complies with the transmission requirements specified in the EN ISO 12312-2:2015 standard

Included components

• Baader ASSF 130 AstroSolar ClearWhite OD 5.1 solar filter
• 3 centering screws with a diameter of 10 mm and a length of 38 mm
• 3 safety straps with self-adhesive mounts
• 32-page operating and installation manual

Technical specifications

• catalogue number: 2423040
• type: front-aperture filter for solar observation
• filter material: AstroSolar® ClearWhite Safety Film
• optical density: OD 5.1
• light transmission: 0.0008%
• clear filter aperture: 130 mm
• recommended instrument aperture range: 120–140 mm
• outer cell diameter: 210 mm
• mounting range inside the optical tube: 168–198 mm
• mounting range outside the optical tube: 148–178 mm
• centering screw diameter: 10 mm
• centering screw length: 38 mm
• weight: 151 g
• application: visual observation and astrophotography
• observed object: Sun

The Baader ASSF 130 provides stable mounting in front of the optical system, enabling safe, detailed visual observation and photospheric imaging.