Canon EF 50mm f/1.8 STM vs f/1.4 USM

Pick the f/1.8 STM if

• You want the lighter lens to carry: 130 g lighter (160 g vs 290 g)
• You shoot video: STM autofocus is smooth and quiet (the f/1.4 USM uses USM)
• You shoot close-ups: it focuses down to 0.35 m vs 0.45 m
• You want bigger close-ups: 0.21× vs 0.15× maximum magnification
• You want a compact lens: 39.3 mm vs 50.5 mm long
• Our notes say it suits: Low-light handheld shooting, everyday walk-around, video with quiet AF

Pick the f/1.4 USM if

• You need ⅔ stop more light for low light or background blur (f/1.4 vs f/1.8)
• You care about the shape of out-of-focus highlights: 8 aperture blades vs 7
• Our notes say it suits: Available-light photography, street and documentary

Our notes

Canon EF 50mm f/1.8 STM

Compact 50mm f/1.8 prime with an STM stepping motor and a metal mount, replacing the older f/1.8 II. Covers full frame and works on APS-C EOS bodies.

Pros

• Fast f/1.8 aperture
• Light and small
• Quiet STM focusing
• Metal lens mount

Cons

• No image stabilization
• Corners soften at f/1.8
• Focus ring is electronic rather than mechanically coupled

Our notes

Canon EF 50mm f/1.4 USM

A fast standard prime from the 1990s with a ring-type USM motor and a metal mount. It sits between the f/1.8 models and the L-series f/1.2 in speed and build.

Pros

• f/1.4 aperture
• Ring USM with full-time manual focus
• Metal mount and solid build
• Compact for its speed

Cons

• Soft and hazy wide open
• Not weather sealed
• Older optical design