Sharpness at 25mm

The sharpness tests for this review were carried out using a real-world subject rather than a test chart. The Olympus M.ZUIKO Digital 25mm f/1.8 lens was attached to an Olympus OM-D E-M1 compact system camera, which in turn was mounted on a sturdy tripod. The self-timer was used to avoid any vibrations from pressing the shutter release. Slight tonal changes are due to slight changes in natural light during the session.

The full frame at 25mm

Centre sharpness is very good wide open and quickly reaches its “sweet spot” at f/4. From f/16, the effects of diffraction start to become visible, but only the f/22 setting produces unacceptable results. The edges follow a similar pattern – sharpness is good wide open, better still at f/4, somewhat worse at f/16 and predictably poor at f/22.

Aperture	Centre Crop	Edge Crop
f/1.8
f/2.8
f/4
f/5.6
f/8
f/11
f/16
f/22