Baader ASTF 240 mm OD 5.0 Solar Filter for Telescope

Baader ASTF 240 mm OD 5.0 Solar Filter for Telescope

DESCRIPTION
The Baader ASTF 240 mm OD 5.0 solar filter is designed for precise white-light solar observation and imaging. It uses the original AstroSolar OD 5.0 safety film, mounted stress-free in a temperature-compensated cell, ensuring optimal optical performance across a wide temperature range.

Unlike tensioned filters that degrade image quality, the ASTF is engineered to preserve the film's diffraction-limited precision. It is ideal for observing fine solar structures such as sunspots at high magnification. The cell includes centering bolts in two lengths and diameters, ensuring secure attachment to a wide range of telescope tubes without tools.

Also included are three safety straps with adhesive pads, rubber plugs for unused holes, and a detailed mounting manual. This filter offers professionals and amateurs alike a safe, stable, and optically superior way to study the Sun.

TECHNICAL SHEET
• Type: AstroSolar OD 5.0 solar filter
• Manufacturer: Baader Planetarium
• Reference: 2459317
• Net weight: 0.28 kg
• Clear aperture: 240 mm
• Outer diameter: 330 mm
• Inner diameter: 240 mm
• Inner clamping range (10 mm bolts): 290 – 320 mm
• Inner clamping range (20 mm bolts): 300 – 330 mm
• Outer clamping range (10 mm bolts): 270 – 300 mm
• Outer clamping range (20 mm bolts): 260 – 290 mm
• Optical density: OD 5.0
• Solar wavelength: White light (broadband)
• Use: High-magnification visual and photographic solar observation

Included: Filter cell, 6 centering bolts (3 × 10 mm and 3 × 20 mm), 3 safety straps with adhesive pads, 3 rubber plugs, instruction manual