Lens Adapter Pixco SB4843 — Canon EOS R (RF) camera to M42 screw-mount lens

The Pixco SB4843 lens adapter allows mounting M42 screw‑mount (42×1) lenses onto Canon EOS R mirrorless cameras with the RF mount. This mechanical adapter creates a stable, precise flange distance so manual-focus and manual-aperture vintage lenses can be used on modern RF‑mount bodies. The adapter preserves the optical characteristics of the attached lens while providing a solid metal connection between lens and camera.

Advantages

The adapter is fully mechanical and does not contain electronic contacts, which maintains full manual control over focus and aperture and ensures compatibility with a wide range of M42 lenses regardless of original camera maker. Its machined metal construction provides repeatable mounting, secure locking, and reliable alignment for consistent image results. The low-profile design minimizes added extension and keeps the adapted lens close to the camera sensor for accurate focusing across the focusing range.

Suitable for

• Photographers who want to use vintage M42 lenses on Canon EOS R series cameras
• Videographers seeking manual aperture and focus control for creative work
• Careful optical testing and lens character studies using legacy glass

Key specifications

• Mount type (camera side): Canon RF mount
• Mount type (lens side): M42 screw mount (42×1)
• Connection: fully mechanical, no electronic contacts
• Material: precision-machined metal construction
• Function: maintains manual focus and manual aperture control of attached lens
• Compatibility: designed for Canon EOS R mirrorless camera bodies

How to use

Attach the M42 lens to the adapter by screwing the lens into the adapter’s M42 thread until secure, then align the adapter’s RF bayonet with the camera’s RF mount and rotate until it locks into place. Set the lens to its desired aperture using the lens aperture ring and focus manually using the lens focus ring. Because there are no electronic contacts, set exposure and autofocus preferences on the camera body manually or use camera manual/exposure modes. Remove the adapter by unlocking the bayonet and unscrewing the lens from the adapter when finished.

Usage recommendations

Use manual exposure or stop-down metering on the Canon EOS R body, and consider enabling focus magnification or focus peaking for accurate manual focusing. Handle the adapter and lenses carefully to avoid cross-threading when attaching or removing M42 screw-mount lenses.