Canon EF 50mm F/1.8 STM

Canon launched this EF-mount prime in 2015, and it remains in production. It covers the full frame format. The single 50mm focal length gives a natural view of people and scenes, an easy match for portraits, candid indoor shots and everyday picture-taking. It also serves as a light second lens beside a zoom.

The fixed focal length is the main trade-off. You change framing by stepping closer or further back rather than turning a zoom ring. Moving also changes perspective, so think about the subject’s surroundings as you choose a position. A zoom offers faster framing changes from a fixed spot.

At 5.6 oz (160 g), this is a lens you can carry all day without noticing it. The body is small too, at 2.72 in (69.2 mm) wide and 1.55 in (39.3 mm) long. On the front, a screw-in filter must match the 49mm thread. Step-up rings can adapt larger filters you already own.

The 50mm focal length sits in the middle of the range. It frames a standing person from a comfortable working distance, so portraits, street scenes and candid documentary shots feel natural. There is no wide angle for tight interiors and no telephoto reach for distant sport.

The f/1.8 maximum aperture is the strongest photographic asset here. Compared with a smaller aperture, it gives you more room to keep shutter speeds usable indoors without raising ISO as far. Dim restaurants and evening events are useful examples. The optics specification score is 82 out of 100.

Wide open, the aperture can deliver shallow depth of field. A portrait subject can separate from a busy background, which helps at parties, markets and on crowded streets. Moving the subject farther from the background strengthens that separation. Stopping down brings more of the scene into focus when context matters more.

Closest focus is 1.1 ft (35 cm), measured from the sensor. That allows close views of food on the table and small still-life setups. For portraits, move farther back to leave a comfortable gap and avoid the exaggerated perspective of very close framing.

This lens has no image stabilization. Sharp handheld results depend on a shutter speed fast enough to stop camera shake. Watch the shutter dial in dim rooms, steady yourself when it drops, or rest the camera on something solid. A tripod or monopod also steadies the camera in very low light.

There is no weather sealing. Rain, sea spray and blowing dust call for cover or a change of plan, which matters if you shoot outdoors through the year. The front element has no fluorine coating either, so fingerprints and water spots need ordinary careful cleaning. A blower and a soft cloth handle it.

The optical path uses just six elements arranged in five groups, all of them conventional glass. The design includes no aspherical, low-dispersion or other special elements. A short, simple layout of that kind suits the compact, light body of this lens.