Last Updated: 2023-01-29


Lens mount

  • RF: for mirrorless
  • EF: dates back to 1987; compatible with every EOS camera ever produced (with adapters). When mounting an EF lens to an APS-C-size sensor, you need to multiply the focal length by 1.6x to work out the equivalent in 35mm terms.
  • EF-S: for APS-C.
  • EF-M: exclusively for EOS M. Even more compact compared to the EF and EF-S.

How to decode Canon lenses

  • Prime: describing a fixed focal length lens, i.e., a lens that doesn’t zoom.
  • USM: Ultra Sonic Motor, quieter and faster than standard motors used in cheaper lenses.
  • STM: stepper motor, a much quieter AF performance, uses fly-by-wire focusing, which means turning the focus ring doesn’t physically move the elements, but tells the AF motor to do so.
  • IS: Image Stabilisation.
  • L-series: top-end, professional-grade lenses.
  • I, II, III: lens’ generation.


"EOS-1D X Mark III is our last DSLR" (introduced in 2020)

  • R: RF mount
    • EOS R3: Full-Frame, 2021
    • EOS R5: Full-Frame, 2020
    • EOS R6: Full-Frame, 2020
    • EOS R7: APS-C, 2022
    • EOS R: Full-Frame, 2018
    • EOS RP: Full-Frame, 2019
  • M: APS-C, EF-M mount

Phone Cameras

Google Pixel 6 Pro:

  • ultra wide camera: 114 field of view, f/2.2 aperture
  • wide camera: 50mp, f/1.85, 1/1.31 image sensor size
  • telephoto camera: 48 MP 1/2 image sensor size


DJI RS 2 / RSC (C=Compact) 2