When it applies
- EOS R5 guide scope: firmware 2.2.0 or later; lens and adapter firmware unspecified.
- RF-S directly attached; EF-S through Canon Mount Adapter EF-EOS R.
- Automatic 1.6x crop, 3:2 only; previous alternate aspect ratios clear. RAW omits the outer image.
- Large JPEG/HEIF and RAW/C-RAW: 17.3 MP (5088×3392). Small2: 3.8 MP (2400×1600).
Where it stops
- Medium and Small1 quality choices are unavailable; preselected Medium becomes Large, and Small1 becomes Small2.
- RF/EF full-frame lenses have different cropping choices; their aspect-ratio RAW behavior must not be transferred here.
- This rule establishes no AF coverage, burst speed, stabilization rating, exposure accuracy, or movie recording modes.
Sources
- EOS R5 Advanced User Guide — firmware scope — Opening paragraph, D090-001. Instructions cover firmware 2.2.0 or later; this is document scope, not the first firmware supporting these lenses. Read 2026-09-07.
- EOS R5 — Still Photo Cropping/Aspect Ratio — D090-039; step 2, both Caution sections. Forced still-image area, quality-menu changes, and actual RAW crop; no movie-mode inference. Read 2026-09-07.
- EOS R5 — Specifications — D090-215; Type; Still photo pixel count table, 1.6x column. Pixel counts depend on image quality. Large and RAW/C-RAW are 5088×3392; Small2 is 2400×1600. Read 2026-09-07.
- EOS R5 — Attaching/Detaching RF Lenses — D090-018; Attaching a Lens steps 2–3. Native attachment and AF/MF selection, including camera-menu selection for lenses without a focus switch. Read 2026-09-07.
- EOS R5 — Attaching/Detaching EF/EF-S Lenses — D090-019; opening paragraph; attachment steps 2–4. R5-specific EF/EF-S adapter support and AF switch instructions. Excludes EF-M; not a speed or stabilization rating. Read 2026-09-07.
- AF Area, by Lens — H001-012; May 2026; EOS R5 column in RF and EF-S tables, five exact lens rows. Each exact row reports approximately 80% horizontal by 80% vertical. This is an AF-area statement, not measured tracking performance or an all-mode guarantee. 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.
- Canon EOS R5 + Canon RF-S 18-150mm F3.5-6.3 IS STM
- Canon EOS R5 + Canon RF-S 18-45mm F4.5-6.3 IS STM
- Canon EOS R5 + Canon RF-S 10-18mm F4.5-6.3 IS STM
- Canon EOS R5 + Canon EF-S 10-18mm f/4.5-5.6 IS STM
- Canon EOS R5 + Canon EF-S 18-135mm f/3.5-5.6 IS USM
Researched from manufacturer documents by an AI agent and source-checked 2026-09-07. How the research works