Canon EF 50mm f/1.8 STM: A Compact Portrait Lens

You can frame a face with a kit zoom and still wish the busy room behind it would fade away. The Canon EF 50mm f/1.8 STM gives a compatible Canon DSLR a wide aperture for that job, without adding a large lens to the bag.

That extra aperture is useful when one person is the subject and the background is the distraction. A crowded room or a changing group still gives a zoom good reasons to stay on the camera.

Make room for the 50mm view

This lens stays at 50mm. To change how much of the scene fits, you need to change your position or the composition; there is no zoom ring to turn when a wall is behind you.

On a full-frame Canon DSLR, it provides the normal 50mm view. On Canon APS-C bodies, including many Rebel cameras, the framing is equivalent to an 80mm lens on full frame. That tighter view can suit a portrait of one person, but it asks for more space when you want several people in the picture.

Canon specifies a closest focusing distance of 0.35 meter and maximum magnification of 0.21x. That leaves room for closer views of everyday objects, but it does not make this a life-size macro lens for tiny subjects.

Use the aperture deliberately

The f/1.8 maximum aperture is the main reason to add this lens. Compared with using a smaller aperture in the same light, opening up gives you room to use a faster shutter speed or lower ISO for the same exposure. It also lets you narrow the zone that appears in focus, helping a face stand apart from its background.

Those choices come together. At close distances, a shallow focus zone makes accurate focus important; a group with faces at different distances may need a smaller aperture. There is no requirement to keep the lens at f/1.8 just because it can open that far.

The lens has no optical image stabilization. A wide aperture can help you select a shutter speed that suits the subject, but it does not cancel hand movement. Keep shutter speed in the decision, especially for moving people or dim rooms.

Manual focus needs power, too. The electronic focusing ring cannot adjust focus with the camera off or the lens asleep. With the camera on, half-press the shutter to wake the lens before focusing.

Check the mount before the accessories

This is the EF 50mm f/1.8 STM for Canon's EF system. It mounts directly on compatible Canon EOS DSLRs. An EOS R mirrorless body needs a separate EF-EOS R adapter, so include that cost and extra length when comparing your options. The similarly named RF 50mm is a different lens.

At 160 grams, the EF lens makes a modest addition to a camera bag. Its metal mount and AF/MF switch are visible in the product photos. The front filter thread is 49mm; filters from another lens will not necessarily fit. Canon's optional ES-68 hood is also a separate purchase.

Keep the lens capped when leaving it in sunlight; concentrated rays can start a fire. Never look at the sun or another bright light through the lens or camera, which can cause loss of vision.

Try the framing before you buy

If your current zoom covers 50mm, set it there and leave it there for a few ordinary photos. Try the room where you actually photograph people. This checks the framing, not the f/1.8 background effect, and can reveal whether limited room to step back will frustrate you.

Look at which pictures you wanted but could not frame: one person's face, a couple on the couch, or everyone around a table. If individual portraits fit comfortably and distracting backgrounds are the remaining problem, the wider aperture has a clear job. If you keep needing a wider view, prioritize a focal length that fits the room.