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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Lunt Solar 1.25" R&P Focuser - Dual Speed

Lunt Solar 1.25" R&P Focuser - Dual Speed

by Lunt Solar Systems
SKU LSS-001-148
$269.00 - $269.00
$269.00
$269.00 - $269.00
$269.00
Price Match Policy!
  • 1.25" Focuser Size
  • 10:1 Dual-Speed Reduction Fine Focus
  • 6-8 pound (2.7-3.6 kg) Load Capacity
  • 0.5" Draw Tube Travel
  • CNC Machined Aluminum and Brass Construction
1 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Lunt Solar 1.25" R&P Focuser - Dual Speed

    The Lunt Solar 1.25" Dual Speed R&P Focuser delivers the mechanical precision required for high-magnification solar and planetary imaging, where atmospheric seeing dictates focus on a moment-to-moment basis. Its integrated 10:1 reduction knob allows for micro-adjustments with a resolution of ±0.0002" per rotation, while the robust rack and pinion drive securely manages a 6-8 pound load with less than 0.0005" of backlash. This CNC-machined focuser provides the critical control needed to snap the finest details into focus within its 0.5" of draw tube travel.

    10:1 Dual-Speed Reduction: Achieving Critical Focus Down to ±0.0002"

    At high magnifications, the critical focus zone can be microns-thin. This Lunt focuser's 10:1 fine-focus knob translates a full turn into an incredibly small drawtube movement, achieving a fine focus resolution of ±0.0002". This level of control is essential for teasing out solar granulation, resolving details in Jupiter's cloud bands (GRS), or splitting tight double stars where a standard focuser would overshoot the mark.

    Zero-Backlash Rack & Pinion Drive: Supporting a 6-8 Pound Imaging Train

    Unlike friction-based Crayford designs that can slip under load, this focuser's rack and pinion drive provides a positive, mechanical engagement. It is engineered to support a 6-8 pound (2.7-3.6 kg) payload without flexure or image shift. With backlash adjustable to less than 0.0005 inches, you can change focus direction without encountering dead zones, ensuring your target remains centered and sharp during an imaging run.

    Rotatable Body & Brass Compression Ring: 360° Framing Flexibility

    The entire focuser body is rotatable, allowing you to orient your eyepiece or camera to the most comfortable angle or to perfectly frame your target without loosening any optical components. The drawtube terminates in a non-marring brass compression ring, which secures your 1.25" accessories firmly without scratching the barrel, preserving the value and finish of your eyepieces and cameras.

    Lunt 10:1 R&P vs. Standard Single-Speed Focusers: An Essential Upgrade

    While a standard single-speed focuser is adequate for low-power viewing, it becomes a point of frustration for high-resolution work. The Lunt 10:1 dual-speed mechanism is not a luxury but a fundamental requirement for critical observation. The coarse knob gets you close, while the fine knob lets you dial in perfect focus without the vibration or over-correction inherent in single-speed systems, making it a mandatory upgrade for any serious solar or planetary observer.

  • How does the Lunt 10:1 focuser improve imaging the Sun's granulation?

    Solar granulation and other surface details are low-contrast features that are only visible in moments of steady atmospheric seeing. The 10:1 fine focus ratio allows you to make minute, controlled adjustments with a resolution of ±0.0002", enabling you to precisely hit the point of sharpest focus during those brief, clear moments without introducing vibration or overshooting the mark.

    Will the Lunt dual-speed focuser's 6-8 pound capacity handle a binoviewer?

    Yes. The 6-8 pound (2.7-3.6 kg) load capacity is more than sufficient for most 1.25" binoviewers and eyepiece pairs. The rack and pinion drive prevents the slippage that can occur with friction-based focusers under the weight of a binoviewer, ensuring your focus remains stable.

    What is the advantage of a Rack & Pinion drive on the Lunt focuser?

    A Rack and Pinion (R&P) drive uses geared teeth for a positive mechanical connection between the knob and the drawtube. This design is superior for heavier loads as it physically cannot slip, unlike Crayford focusers which rely on friction. This makes the Lunt R&P ideal for imaging setups or heavy visual accessories.

    Is the 0.5" draw tube travel on the Lunt focuser enough for my eyepieces?

    The 0.5" (12.7mm) travel is designed for fine-tuning focus on Lunt solar telescopes, where the primary focus position is relatively fixed. It is generally sufficient for a set of eyepieces that are close to parfocal. However, if you are switching between accessories with vastly different focal points, you may need to use the telescope's main focuser or extension tubes to achieve initial rough focus.

    What does the "rotatable" feature on the Lunt 1.25" focuser do?

    The entire focuser body can be rotated 360 degrees relative to its mounting base. This allows you to position the focusing knobs for comfortable access or to rotate your camera to achieve the best composition for your target without having to loosen the camera or eyepiece in the drawtube.

    How do I adjust the backlash on the Lunt 10:1 focuser?

    The focuser is designed for minimal backlash of <0.0005 inches when properly adjusted. Typically, small set screws on the focuser body allow you to adjust the tension and mesh of the pinion gear against the rack. This ensures immediate response when you change focusing direction, which is critical for tracking moving targets or reacting to changing seeing conditions.

  • Focuser Size 1.25"
    Drive System Rack and Pinion
    Fine Focus Ratio 10:1 reduction
    Load Capacity 6-8 pounds (2.7-3.6 kg)
    Draw Tube Travel 0.5"
    Positioning Accuracy ±0.001 inches (±0.025mm)
    Fine Focus Resolution ±0.0002" per knob rotation
    Backlash <0.0005 inches when properly adjusted
    Rotatable Body Yes
    Compression Ring Yes
    Materials CNC machined Aluminum and Brass
    Coarse Focus Resolution Standard rack engagement
    Parameter Value

    • Lunt Solar 1.25" R&P Focuser - Dual Speed

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  • Lunt Solar Systems 5-Year Warranty