Off-axis Guide Star Set 1.25-inch Double Helix Focusing Astronomy

Key Benefits

• Enables real-time guiding during long-exposure astrophotography without disturbing the main telescope
• Double helix focusing provides smooth, precise movement with minimal backlash
• 1.25-inch standard size fits most amateur and semi-professional telescope focusers
• Guide star position can be adjusted without moving the main optical axis
• Reduces tracking errors caused by mechanical flex or thermal drift in the telescope system

Application Scenarios

• Long-exposure deep-sky imaging with a Newtonian or refractor telescope using a guide scope
• Mounting a guide camera on a 1.25-inch focuser without requiring a separate guide scope
• Fine-tuning guide star alignment during polar alignment or drift alignment
• Using the set in a dual-camera setup where the main camera captures the target and the guide camera tracks a star
• Adjusting guide star position during imaging sessions without repositioning the telescope

Who It Is For

• Amateur astrophotographers doing deep-sky imaging
• Educational astronomy labs using small to medium telescopes
• Amateur astronomy clubs conducting imaging sessions
• University teaching labs demonstrating telescope guiding techniques
• Independent researchers conducting long-duration observational tests

Problems It Solves

• Manual guiding with a hand controller leads to tracking errors over time
• Fixed guide star positions cause misalignment when the telescope moves due to thermal expansion or mechanical flex
• Lack of fine adjustment in standard guide star holders results in poor tracking accuracy
• Separate guide scopes require additional mounting hardware and alignment steps
• Inability to adjust the guide star position without moving the main telescope axis

Technical Features

• 1.25-inch diameter for compatibility with standard telescope focusers
• Double helix focusing mechanism for smooth, backlash-free adjustment
• Adjustable guide star position via a precision focusing knob
• Mounts directly on the 1.25-inch focuser without requiring additional adapters
• Designed for use with guide cameras or guide eyepieces in a secondary optical path
• Constructed from machined aluminum with a black anodized finish for reduced light scatter

Specifications

Specifications are taken from the AMADA product data for this item. Confirm critical dimensions with us in writing before ordering.

Customization Options

• Available in standard 1.25-inch configuration
• Can be supplied with or without a guide eyepiece holder
• Optional replacement of the focus knob with a different gear ratio if needed
• Can be adapted to other standard sizes upon request (e.g. 2-inch, 0.965-inch) with a custom quote

Comparison With Other Options

Use Guide

• Attach the guide star set to the 1.25-inch focuser of the telescope before imaging
• Insert the guide camera or eyepiece into the 1.25-inch barrel of the set
• Use the double helix knob to adjust the guide star position until it is centered in the field of view
• Lock the focus by tightening the retaining ring if required, or leave it free for continuous adjustment
• Use the guide star position to correct tracking errors during long-exposure imaging