Sigma 90mm F/2.8 DG DN | C

This 90mm prime serves full-frame mirrorless photographers in Sony E and Leica L mounts. Sigma introduced it in 2021, and it is still in production. It suits portraits, street work and quiet details rather than sport or wide landscapes.

A short telephoto view makes the subject larger while keeping a natural working distance, so faces stay relaxed and you have room to compose. The trade-off is clear. You accept one focal length and a modest f/2.8 maximum aperture in return for a very light, very small lens. That makes it a natural second lens beside a standard zoom.

At 10.4 oz (295 g), this is a very light lens for a full-frame telephoto. The 2.35 in (59.7 mm) length and 2.52 in (64 mm) width keep the overall package small. It earns a physical score of 93.

The front thread takes screw-in 55mm filters, so a polariser or ND filter fits directly on the lens.

At 90mm, the lens frames head-and-shoulders portraits from a comfortable few steps away. That distance keeps perspective natural and leaves you room to direct a subject or stay unnoticed on the street.

The narrow view also helps simplify busy scenes by isolating one subject from its surroundings. It suits details, market stalls and garden shots where stepping closer is not an option.

The f/2.8 maximum aperture gives enough light for shaded streets and evening interiors. It also softens busy backgrounds behind a portrait, though a wider aperture would isolate more strongly. At f/2.8, depth of field is shallow enough that precise focus on the eyes matters. Stopped down, nine aperture blades help keep the opening round, which keeps out-of-focus areas smooth.

Closest focusing is 1.6 ft (50 cm), close enough to fill the frame with a face or a still-life setup on a table. Maximum magnification is 0.2x, a level that suits flowers, food and texture studies.

The barrel carries weather sealing, so light rain and dust are less of a concern on outdoor shoots. A shower at a roadside market becomes easier to shrug off.

There is no image stabilization, so shake correction depends entirely on the camera body. If your camera does not stabilize the sensor, a tripod or monopod is the practical fallback for slower work in dim light.

The front element also has no fluorine coating, so rain spots and fingerprints may need more deliberate cleaning, and a soft cloth handles most of it. The features score for this lens is 32.

Inside are 11 elements in 10 groups, including aspherical and low-dispersion glass. The aspherical surfaces are designed to help correct distortion, which otherwise curves straight edges, and spherical aberration.

The low-dispersion glass is designed to help reduce chromatic aberration, the coloured fringes that can appear along high-contrast edges such as backlit hair. Focusing is internal, so the barrel keeps a constant length as focus changes.