OLMPUS M.Zuiko Digital ED 12-45mm f/4 Pro Lens

Olympus says that the 12-45mm f/4 employs an optical formula based on its existing M.Zuiko Digital ED 12-40mm F2.8 Pro (replaced by the M.Zuiko Digital ED 12-40mm F2.8 Pro II with uprated weather sealing in February 2022) which is an enticing prospect given that this one of the finest standard zooms available. Detailed examination shows that the new lens’s 12-element, 9-group formula is indeed very closely related to its sibling’s 14-element, 9-group design.

It makes similarly lavish use of special glass, too, incorporating aspheric, dual super-aspheric (DSA), high refractive index (HR), super-high refractive index and Extra-low Dispersion (ED) elements into its construction, in order to minimise optical aberrations. Meanwhile Olympus’s Zero coating is applied to suppress flare and ghosting. It’s difficult to think of another small zoom with a similarly ambitious design.

As part of the premium Pro series, the 12-45mm F4 is also designed to be dust-, splash- and freeze-proof, with a range of seals protecting vulnerable points such as the front element, manual-focus and zoom rings, and mount.

One feature it gives up relative to the firm’s other Pro zooms, though, is the push-pull focus clutch; instead it employs a simple, continuously rotating electronic manual focus ring. This drives a single focusing element that’s placed towards the rear of the lens, which also affords rapid, silent autofocus.

The aperture diaphragm employs seven curved blades in a bid to provide attractive background blur. However with the f/4 maximum aperture giving equivalent depth-of-field characteristics to f/5.6 on APS-C and f/8 on full-frame, you won’t see a huge degree of blur, except during close-up shooting.