Skip to content
Price match 30-day returns* Talk to an astronomer before you buy
William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame
William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame
William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame
William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame
William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame

William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame

by William Optics
SKU WO-YE-TR-BR48-C
CA$149.00 - CA$149.00
CA$149.00
CA$149.00 - CA$149.00
CA$149.00
Price Match Policy!
  • Solid Copper Construction for Maximum Rigidity
  • M48 (2") Female Thread for Wide-Field Correctors
  • Connects to Canon EOS Camera Bodies
  • Precise 10.6 mm Optical Path Length
  • Eliminates Flexure in Heavy Imaging Trains
1 in stock
Qualifies for FREE Shipping in Canada on orders over $500.
Vignetting Calculator

Will your imaging train vignette?

Check which filter and adapter sizes clear the sensor with the William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame, and how much light the corners lose.

Check vignetting
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame

    The William Optics Super High Precision COPPER T-Mount provides a rigid, M48-threaded connection for Canon EOS cameras with a precise optical length of 10.6 mm. This solid copper adapter is engineered for a rigid connection to the camera.

    Copper Construction: A Zero-Flexure Foundation for Your Imaging Train

    Unlike standard aluminum T-rings that can bend or shift under the weight of a heavy camera and filter wheel, this William Optics T-mount is machined from solid copper. This material choice provides a significant increase in rigidity, preventing tilt and ensuring your camera sensor remains perfectly orthogonal to the optical axis for sharp, round stars across the entire frame.

    M48 Threading for Full-Frame Canon EOS Cameras

    This adapter features the larger M48x0.75 thread standard on the telescope side, not the smaller M42 T-thread. This wider aperture is essential for full-frame Canon EOS cameras, as it prevents vignetting by providing an unobstructed light cone to the large sensor. It creates a secure, wide-format connection to modern field flatteners and reducers.

    Copper vs. Aluminum T-Rings

    An aluminum T-ring is lighter; copper is heavier and stiffer. Over the 10.6 mm optical length, the difference in thermal contraction between copper and aluminum is around a micron for a 20 C temperature drop, far too small to affect focus.

    • Aluminum: Standard aluminum T-rings are lighter and less expensive.
    • Copper: The copper construction is stiffer than aluminum, for flexure resistance with heavy camera setups.

  • Why is this William Optics T-Mount made of copper?

    Copper is stiffer than standard aluminum, which helps resist flexure in the imaging train with heavy camera setups.

    What is the benefit of the M48 thread on this T-mount for my Canon EOS camera?

    The larger M48 (2-inch) thread provides a wider, unvignetted light path to full-frame sensors. This is a significant improvement over standard M42 T-threads, which can cause dark corners in images taken with full-frame cameras like those using the Canon EOS mount.

    Will the 10.6mm optical length of this William Optics mount work with my flattener?

    The 10.6mm optical length is designed to be part of a standard 55mm backfocus calculation. Always check the requirements for your specific flattener or reducer, but this T-mount is designed to integrate cleanly into common M48-threaded imaging trains.

    Which camera mount does this William Optics T-Mount fit?

    This specific model connects to a Canon EOS camera mount. It is designed to adapt M48-threaded accessories to Canon EOS camera bodies. William Optics produces different models for various camera brands.

    Does the copper construction of the William Optics T-Mount help focus on a cold night imaging the Orion Nebula (M42)?

    Not measurably. Over the T-mount's 10.6 mm length, copper and aluminum differ in thermal contraction by around a micron for a 20 C drop, far too small to change focus. Focus drift on a cold night comes from the telescope itself, so refocus as the temperature falls.

    Does the extra weight of the copper T-mount matter?

    While copper is heavier than aluminum, the small size of the T-mount means the weight difference is minimal and will not affect the balance of most telescope setups. The added rigidity and stability are a worthwhile trade-off for the slight increase in weight.

  • Telescope Side Connection M48 (female)
    Camera Side Connection Canon EOS Camera Mount
    Optical Length 10.6 mm

    • William Optics Super High Precision COPPER T-Mount

      × 1

  • William Optics 2-Year Warranty