Nanjing AMADA Instrument Co., Ltd. · Nanjing, China [email protected] · +86-15195807515
AMADA Microscopes Request A Quote
Home Products Biological MicroscopeZoom Stereo MicroscopeFluorescence MicroscopeMetallurgical MicroscopePolarizing MicroscopeVideo Digital MicroscopeMicroscope CameraAstronomy AccessoryMicroscope AccessoryMagnifier Knowledge About Contact Request A Quote
Home / Products / Astronomy Focuser / K005 Double Spiral Focusing Seat Externa
K005 Double Spiral Focusing Seat External T-mount Ring for Telescope

K005 Double Spiral Focusing Seat External T-mount Ring for Telescope

The K005 Double Spiral Focusing Seat External T-mount Ring is a 1.25-inch all-metal focuser designed for astronomical telescopes and telephoto lenses. It features a 10mm focusing stroke with 0.1mm precision, enabling smooth, linear movement during focusing without rotating the eyepiece or mirror. The double-helix mechanism ensures stable, micro-precise adjustments ideal for high-magnification observation and astrophotography.

  • All-metal construction ensures durability and long-term reliability under field use
  • Double-helix focusing mechanism provides 0.1mm precision and smooth linear motion
  • 10mm focusing stroke with minimal backlash for fine adjustments at high magnification
  • Non-rotating eyepiece or mirror movement maintains alignment during focus
  • Compact design (56–66mm length) fits tight optical train spaces
Request A Quote +86-15195807515

Technical features

  • 1.25-inch outer diameter with M42×0.75 external thread (internal thread M42×0.75 must be specified in order)
  • Double-helix fine-tuning mechanism for high-precision focusing
  • Focusing stroke: 10mm with 0.1mm accuracy
  • Minimum length: 56mm; maximum length: 66mm
  • Main mirror interface: M42×0.75
  • All-metal construction for durability and heat resistance
  • Non-rotating movement of inserted CDD eyepiece or zenith mirror
  • Designed for use with guide scopes, viewfinder mirrors, or telephoto lenses

Who it is for

  • Astronomy hobbyists building or upgrading telescope systems
  • Importers sourcing precision focusing accessories for telescope kits
  • Distributors adding high-precision focusers to their optical accessory catalog

Specifications

ModelK005
Interface1.25 inches with M42×0.75 external thread
Main Mirror InterfaceM42×0.75
Focusing Stroke10mm
Accuracy0.1mm
Minimum Length56mm
Maximum Length66mm
MaterialAll metal
Thread TypeExternal M42×0.75 (internal M42×0.75 required for order note)

Use guide

  • Confirm whether internal or external M42×0.75 thread is needed before ordering
  • Install on guide scope or viewfinder with M42×0.75 interface using the external thread
  • Use with CDD eyepieces or zenith mirrors to maintain alignment during focus
  • Adjust focus slowly using the double-helix knob for micro-precision at high magnification

FAQ

What thread type does this have?
External M42×0.75. Specify internal M42×0.75 if needed in the order note.
Does the eyepiece rotate during focusing?
No. The double-helix design ensures linear movement only, preserving alignment.
What is the focusing stroke?
10mm with 0.1mm accuracy for precise adjustments.
Is it suitable for astrophotography?
Yes. The non-rotating focus and high precision make it ideal for imaging setups.
Can I use it with a telephoto lens?
Yes. It fits telephoto lenses with M42×0.75 interface for focus control.

Related products