Lunt Blocking Filters

• The required safety component for every Lunt H-alpha solar system—each blocking filter houses additional elements essential to safe, on-band performance

• Available in four clear-aperture sizes—B600, B1200, B1800, B3400—so you can match your use (visual or imaging) and your telescope’s focal length

• Choose your housing style to fit your workflow: 1.25" or 2" diagonal (with T2), or 2" straight-through extension tube (with T2 and 2")

• Imaging made easy: most camera trains need extra back focus, so select the next larger blocking filter than you would for visual to keep the full cone in-band

• Engineered by Lunt with a unique internal filter stack; safety and performance are warranted only when paired with a Lunt H-alpha filter or telescope

• Works beautifully with Lunt modular scopes and etalon systems; simple, reliable path to crisp prominences, filaments, and high-contrast surface detail

• Quick pick: select B600/B1200/B1800 from the options; the B3400 is available in a 2" straight-through extension tube for long focal lengths

Specifications

• Aperture Options (clear aperture): B600, B1200, B1800, B3400

• Housings:

  • 1.25" diagonal with T2 connection

  • 2" diagonal with T2 connection

  • 2" straight-through extension tube with T2 and 2" interfaces

• Focal Length Guidance (Visual):

  • B600: up to 600 mm

  • B1200: up to 1200 mm

  • B1800: up to 1800 mm

  • B3400: up to 3400 mm

• Focal Length Guidance (Imaging): (choose the next larger size vs. visual due to added back focus and moving the BF up the light cone)

  • B600: up to 400 mm

  • B1200: up to 600 mm

  • B1800: up to 1200 mm

  • B3400: up to 1800 mm

• Use Case: Visual and imaging with Lunt H-alpha systems

• Warranty/Safety: Lunt can only warrant safety and performance when used with Lunt H-alpha filters/telescopes

What’s in the Box?

• Lunt Blocking Filter in your selected aperture (B600 / B1200 / B1800 / B3400)

• Chosen housing: 1.25" or 2" diagonal (T2), or 2" straight-through extension tube (T2 + 2")