Sharpness at 27mm

For this test, the Fujifilm XF 27mm F2.8 R WR lens was attached to a Fujifilm X-E4 body, which was in turn mounted to a sturdy tripod. Exposure delay mode was activated. Tonal and colour variance across the crops are due to change in natural light during the session.

The full frame at 27mm

The centre is sharp wide open, with peak performance achieved in the f/4-8 range. Diffraction sets in at at f/16.

The edges are soft though from f/2.8 through to f/4, only sharpening up at f/5.6, with f/8-11 the optimum settings.

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