Canon R3 Card Slots: Dual CFexpress Type B Guide

The Canon EOS R3 boasts dual Canon R3 card slots, both CFexpress Type B for blistering 6K RAW video and 30fps burst shooting. No SD compromises here – pro-level redundancy and speed.

Explore specs, compatibility, and why dual slots matter for sports/wildlife pros in 2026.

Dual Slot Specs and Benefits

Slot 1 primary, Slot 2 overflow/mirror.

  • CFexpress Type B only (no SD)
  • 6.2K 60p RAW internal
  • 195MP HEIF bursts
  • Backup prevents data loss

Best CFexpress Cards for R3

Speed class 4.0+ recommended.

  • Lexar Diamond 4.0 1TB
  • Delkin Black 4.0 512GB
  • Wise Advanced 2TB
  • Angelbird Match Quick 1TB

Slot Configuration Options

Menu-customizable modes.

  • RAW to Slot 1, JPEG Slot 2
  • Mirror both slots
  • Auto switch on full
  • Separate video/stills

Firmware Updates and Future-Proofing

2026 outlook strong.

  • Firmware 2.0 added proxy recording
  • CFexpress 4.0 support rumored
  • R3 Mark II may add SD slot 4
  • Battery life optimized dual slot