Sharpness at 16mm

For these sharpness tests the Fujifilm 16mm lens was attached to a Fujifilm X-T3 body, which in turn was mounted on a sturdy tripod. Slight tonal changes are due to slight changes in natural light during the session.

The full frame at 16mm

The centre of the frame is remarkably sharp wide open, with peak performance achieved in the f/4-f/11 range. Diffraction sets in at f/16. The edge performance isn't quite as good, being acceptably sharp at f/5.6, with optimum results from f/8-f/11.

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