Standard Canon adapter preserves documented EF lens functions

When it applies

Use the standard Mount Adapter EF-EOS R, seated and locked at both interfaces, without extenders or other optical accessories.
For autofocus, set the lens switch to AF; MF disables autofocus.
Retained functions are interpreted within each camera's documented mode and firmware scope.

Where it stops

RF/RF-S, EF-M and CN-E lenses, third-party EF lenses, and other adapters are outside this rule.
No inference of identical DSLR and mirrorless focus speed, AF coverage, subject tracking, video behavior, or every special lens function.
Canon warns that some EF lenses do not support certain functions; the EF50 E-TTL Auto ISO ceiling exception is recorded separately.
RP is absent from the opened maximum-speed lens table; do not transfer R6 Mark II/R8/R5 Mark II burst eligibility to RP.

Sources

Canon RF Lens World: Mount Adapter EF-EOS R — Mount Adapter EF-EOS R; adjacent specification and exclusions footnote. Standard adapter retains EF lens AF, lens IS, and camera dial operations. The footnote warns that some EF lenses lack certain functions; it is not an all-features or equal-speed guarantee. Read 2026-09-07.
EOS R6 Mark II: Attaching and Detaching EF/EF-S Lenses — D243-021; introduction and Attaching a Lens step 4. Exact body permits EF lenses through Mount Adapter EF-EOS R; AF requires lens AF switch. EF-M excluded. Read 2026-09-07.
EOS R8: Attaching and Detaching EF/EF-S Lenses — Attaching and Detaching EF/EF-S Lenses; introduction and step 4. Exact body adapter instructions and AF/MF switch condition. Read 2026-09-07.
EOS R5 Mark II: Attaching and Detaching EF/EF-S Lenses — Attaching and Detaching EF/EF-S Lenses; introduction and step 4. Exact body adapter instructions and AF/MF switch condition. Read 2026-09-07.
EOS RP specifications — Lens Mount; AF Modes; Manual Focus; Metering modes. Exact body names standard adapter, body AF and focus peaking, and sensor metering. AF coverage varies with lens; no coverage percentage is transferred to the packet. Read 2026-09-07.
EF 50mm f/1.8 STM specifications — Optical Features / Specifications: model title, AF Actuator. Exact EF lens identity and STM autofocus actuator. Page does not explicitly establish an optical IS feature. Read 2026-09-07.
EF 24-70mm f/2.8L II USM specifications — Optical Features / Specifications: model title, AF Actuator and footnote. Exact EF lens and Ring USM / full-time manual focus identity. No stabilization strength for an adapted body. Read 2026-09-07.
EF 70-200mm f/2.8L IS III USM product information — Highlights; Overview; Benefits. Exact EF lens identity and optical Image Stabilizer. Advertised lens stop figure is not applied to the adapted configurations. Read 2026-09-07.

Pairs checked under this rule

Only these pairs were checked. The rule does not extend to other gear on its own.

Researched from manufacturer documents by an AI agent and source-checked 2026-09-07. How the research works