Sigma 50mm F/1.4 DG DN | A

The Sigma 50mm F/1.4 DG DN | Art is a fast standard prime for full-frame mirrorless cameras. Sigma offers it in Leica L and Sony E mounts, so choose the version made for your system. A 50mm focal length suits portraits, street work and everyday subjects. It appeals to anyone who wants one fast lens for people and low light.

Sigma introduced this lens in 2023. The main trade-off is the fixed focal length. You change position to adjust framing, so check whether the view fits your intended subjects and the available space. Walls, tables or barriers can limit how far you can move.

The L-mount version weighs 1 lb 7.6 oz (670 g) and measures 3.08 in (78.2 mm) across and 4.31 in (109.5 mm) long. The Sony E version differs in weight and length. Allow room for the hood and caps when packing. Screw-in filters must match the shared 72mm front thread.

On full frame, 50mm gives a standard view for people and everyday scenes. How much fits depends on where you stand. Moving closer makes the subject larger and changes perspective, with near features becoming larger relative to the background. Check the borders for distractions after changing position.

The f/1.4 maximum aperture admits more light than a smaller opening. At a given shutter speed, it can allow a lower ISO in dim interiors or evening streets. A close subject can stand out against a soft background when there is enough space behind it. Focus carefully on the important detail.

Stop down when more depth of field is needed for a group or tabletop scene, then check the resulting shutter speed. Closest focus is 1.5 ft (45 cm), measured from the sensor. This range can help with meals, flowers and objects on a table. Leave room ahead of the lens for light.

The fixed view encourages planning around your shooting position. If a person moves closer, you may need to change position or accept a tighter composition. Refocus when the subject or camera moves.

The lens is sealed against dust and moisture, which supports outdoor portrait and street work when conditions turn damp or dusty. That matters for seaside and countryside shoots where grit and moisture-laden air are common.

The front element has a water- and oil-repellent coating to help with cleaning. Remove loose grit before wiping the glass. Check for fingerprints when photographing towards a bright lamp, and dry the exterior before storage after a damp session.

There is no image stabilisation in the lens. A camera with body stabilisation can help with shake. Firm support helps with long exposures of still scenes, but a moving person can continue to blur. Choose shutter speed for the subject as well as your own hold.

The optical design includes three aspherical elements, including one with two aspherical surfaces, and one SLD element. Aspherical surfaces help correct distortion and spherical aberration. SLD glass helps reduce coloured fringes along high-contrast edges, such as a backlit portrait. These design choices do not establish measured image quality.