OM System ED 45mm f/1.2 PRO

OM System made this prime for Micro Four Thirds cameras, and portraiture is its natural work. On that format, 45mm acts as a short telephoto, letting you frame a face from a comfortable distance. Wedding and event photographers get a discreet lens for people in varied light. Its f/1.2 aperture defines that role.

The trade-off is the single focal length. You change framing by moving rather than zooming, which suits deliberate portrait work. There is no built-in stabilisation, and the design dates from 2017. It is an established lens rather than a new release.

At 14.5 oz (410 g) it stays comfortable on a compact body through a long shoot. The 2.76 in (70 mm) width and 3.34 in (84.9 mm) length make it short for such a fast prime. Screw-in filters must match the 62mm thread.

The 45mm focal length gives the working distance of a short telephoto. Faces keep natural proportions, and your subject can relax instead of posing at close quarters. It also frames half-body and seated poses without crowding. The reach suits candid detail shots across a room.

The f/1.2 maximum aperture is the headline specification. It admits far more light than a smaller maximum, so indoor portraits stay practical in dim reception rooms and window-lit interiors. It also lets you work without flash where a burst would spoil the mood.

Depth of field at f/1.2 is shallow even on the smaller sensor. A head-and-shoulders portrait separates cleanly from a busy background, and backgrounds dissolve into soft blur. Place your focus point on the near eye, because the zone of sharpness is narrow.

Nine aperture blades keep the opening rounder when you stop down, so out-of-focus highlights at night stay smooth rather than forming hard-edged shapes. Focusing reaches 1.6 ft (50 cm), which covers portrait distances well. Small details such as hands or a bouquet stay in range too. The optics specification scores 88.

Weather sealing guards the lens against dust and moisture. Outdoor portrait sessions can continue through light rain or at a windswept coast, and the sealed body gives confidence on a working day.

There is no image stabilisation inside the lens. At 45mm, handheld shooting is steadier than with a long telephoto. Dim venues still leave you relying on the camera body or your own steady hold. The features specification scores 32.

The front element has no fluorine coating. Rain spots and finger marks will not shed as easily as on coated glass, so keep a cleaning cloth in the bag. A protective filter screws straight onto the 62mm thread if you want extra front-glass protection.

One aspherical element has a specially shaped surface that helps correct distortion and spherical aberration. A single ED element and a single Super ED element use low-dispersion glass. This glass helps reduce colour fringing along high-contrast edges such as rim-lit hair against a bright sky.