LUNT B1200s Blocking-Filter in extension tube

Lunt BF1200S 1.25 Extension Tube

Description
The Lunt BF1200S blocking filter in a 1.25" extension tube is an essential part of a safe and complete solar observing system. Used in combination with a front-mounted etalon filter, it ensures the suppression of UV, IR, and out-of-band light, protecting the observer’s vision or imaging sensor.

Unlike diagonal versions, this straight-through model is designed for configurations that do not require an angled view. It is especially well-suited for camera-based solar imaging or direct viewing with straight focusers.

With a 12 mm clear aperture, the filter supports refractors with focal lengths up to approximately 1080 mm. The rear end offers both a T2 thread and 1.25" eyepiece compatibility, enabling flexible and secure connections.

Technical specifications
• Product reference: 0553009
• EAN: 4007922035833
• Clear aperture: 12 mm
• Format: 1.25" straight extension tube
• Central wavelength: H-alpha 656.28 nm
• Use: Visual and solar imaging
• Telescope compatibility: up to 1080 mm focal length
• Connections: T2 thread and 1.25" barrel
• Housing: Black anodized aluminum

User benefits
• Full protection from harmful wavelengths
• Straight-through format ideal for cameras or direct viewing
• Compatible with all Lunt front H-alpha filters
• Robust and compact build
• T2 threading for direct image train integration

Additional information
• Must always be paired with a Lunt front etalon
• Not a standalone solar filter
• Suitable for advanced or professional users
• Ideal for chromospheric solar detail capture