Canon

Canon 3442C002 EF-EOS R Adapter: Polarizing Filter

4.5 (105 reviews)

Seamlessly mount your EF and EF-S lenses on EOS R mirrorless bodies with built-in circular polarizing filter control.

$258.99*$359.00Save 27%
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*Price sourced from Amazon.com. Last updated:Jun 04, 2026.Price and availability are subject to change.

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Overview

The Canon Drop-in Filter Mount Adapter EF-EOS R bridges the gap between Canon's extensive EF and EF-S lens library and the newer EOS R mirrorless camera system. What sets this adapter apart from Canon's standard mount adapter is the integrated drop-in filter slot, which accepts a circular polarizing filter positioned between the lens and sensor. This design is particularly valuable for photographers using ultra-wide-angle lenses or lenses with bulbous front elements that cannot accommodate traditional screw-on filters, effectively giving every compatible lens instant access to polarization control.

Built with the same level of durability expected from Canon's professional accessories, the adapter features metal mounts on both the lens and camera sides and a dust- and water-resistant seal. Full electronic communication is maintained, so autofocus speed, image stabilization, and aperture control all function as they would with native RF lenses. The polarizing filter is adjusted via a small dial on the exterior of the adapter, allowing photographers to rotate the filter without removing the lens. For EOS R system shooters with an existing collection of EF glass, this adapter offers a practical and high-quality way to continue using those lenses while gaining added creative control through the built-in polarizer.

Key Features

Allows EF/EF-S Lens compatibility with the EOS R camera

Drop-in filter Adapter allows use of circular polarizing Filters

Dust- and water-resistant

Exterior design matched to EF lenses

Metal mount on both Lens and camera sides provides rugged flexibility

Specifications

Compatibility
Canon EF and EF-S lenses to EOS R bodies
Included Filter
Circular Polarizing Filter (drop-in)
Mount Material
Metal (both lens and camera sides)
Weather Sealing
Dust- and water-resistant
Exterior Design
Matched to EF lens styling

Pros & Cons

👍 Pros

  • Includes a built-in circular polarizing filter that works with any attached lens regardless of front element size
  • Dust- and water-resistant construction matches the durability of professional EF lenses
  • Metal mount on both lens and camera sides ensures a secure, wobble-free connection
  • Maintains full electronic communication for autofocus, IS, and aperture control
  • Drop-in filter design lets you add polarization to lenses that cannot accept front-mounted filters

👎 Cons

  • Significantly more expensive than the standard EF-EOS R adapter without the drop-in filter slot
  • Adds length and some weight between the lens and camera body compared to native RF lenses
  • The circular polarizing filter must be rotated via a small external dial, which can be fiddly to adjust precisely
  • Only compatible with Canon EOS R system bodies, not usable with other mirrorless mounts

Frequently Asked Questions

This adapter supports all Canon EF and EF-S lenses, allowing them to be used on Canon EOS R series mirrorless camera bodies.
This adapter comes with a circular polarizing filter. Canon sells other drop-in filter versions separately (such as the variable ND filter version), but the filters are specific to the drop-in mount system and are not interchangeable with standard threaded filters.
No. The adapter maintains full electronic communication between the lens and camera body, preserving autofocus, image stabilization, and aperture control functionality.
The adapter features dust- and water-resistant construction, making it suitable for use in challenging shooting conditions alongside weather-sealed lenses and bodies.
The adapter does not add any optical elements that change focal length. However, EF-S lenses will still produce a cropped image on full-frame EOS R bodies, just as they would on APS-C bodies.