When you start comparing Canon’s mirrorless lineup, one of the first technical differences you’ll notice is how the shutter works. For photographers who want silence, speed, or durability, the choice between mechanical, electronic first-curtain (EFCS), and full electronic shutter matters a great deal. Across Canon’s EOS R range, each model implements shutter technology a little differently, reflecting its market position and price point. The Canon EOS R100 is the most limited.