OM System M.Zuiko Digital ED 12-45mm f/4.0 PRO

This OM System zoom, released in 2020, covers 12–45mm on Micro Four Thirds. That span runs from a wide view of a street scene to a short telephoto for people, so it suits travel and everyday photography from one lens.

The main trade-off is the f/4 maximum aperture. It narrows your options in dim light and softens the background-blur effect at portraits.

Photographers who carry one lens all day, from city streets to mountain trails, are the natural audience. Its light weight and sealing make it a practical choice for that kind of travel.

At 9 oz (254 g), 2.5 in (63.4 mm) wide and 2.76 in (70 mm) long, the lens adds little weight to a kit. A 58mm screw-in filter threads directly onto the front, a common size shared with many lenses.

The 12mm end suits tight interiors, architecture and broad landscapes, where it takes in whole rooms and skies. At 45mm you get a short telephoto that frames one person rather than the crowd. Between those points, the lens covers most everyday framings without swapping.

The maximum aperture stays at f/4 across the whole zoom, so exposure settings carry over at any focal length. That consistency matters when you zoom mid-shoot, moving from a wide scene to a candid portrait.

That f/4 limit is the main optical constraint. On this format it keeps generous depth of field, which helps landscape work. For portraits at 45mm you can still blur a background when you stand close, but the effect is gentler than a faster lens gives. Indoors after dark, plan on raising ISO.

Closest focusing is 0.4 ft (12 cm), close enough for food, flowers and small products. Maximum magnification is 0.25x, so a flower head fills a good part of the frame. Our optics score for this lens is 67/100.

Sealing against dust and moisture runs through the construction. Drizzle on a harbor walk or dust on a trail need not end the shoot. That suits coastal and upland days where weather changes fast.

The lens has no built-in stabilization, so handheld work in low light depends on the camera body or a support such as a tripod. At 45mm in fading light, that support matters most.

No zoom lock is provided, and the front element carries no fluorine coating, so water and oil will not bead off the glass. Keep a cloth handy in damp weather. Our features score is 32/100.

Two aspherical elements, one of them bi-aspherical, help correct distortion and spherical aberration, which matters most at the 12mm end where straight walls can bow. Two low-dispersion elements help reduce chromatic aberration, easing the colour fringes that can appear along backlit branches and window frames.

Focusing is internal, so the barrel does not extend as you focus, keeping a steady working length for close and distant frames. Our construction score is 69/100.