Canon's beloved EF pancake lens, one of the thinnest Canon lenses ever made.
The Canon EF 40mm f/2.8 STM is Canon's full-frame pancake lens, launched in 2012. At just 22.8mm long it barely protrudes from the camera body, transforming the bulk of even a full-frame Canon DSLR. The 40mm perspective is slightly wider than 50mm and increasingly appreciated as a natural everyday focal length.
Optical quality is good with sharp centre performance from wide open. On full-frame the corners soften but for a pancake this is exceptional. On APS-C it provides a 64mm equivalent with excellent sharpness across the frame. STM motor is quiet for video. Build is minimal plastic but the lens is so small there is little to break.
Canon EF mount, 52mm filter thread. Full-frame coverage means it works on all EOS bodies. On RF mirrorless via adapter it functions but the adapter adds thickness, negating much of the pancake benefit. The EF-S 24mm f/2.8 STM is the APS-C equivalent.
Very affordable used. Check the STM motor and aperture blades. The lens is extremely simple with very little to go wrong. Outstanding value for street photography and travel where a minimal kit is desired. A genuine classic in the Canon lineup.