Sharpness at 35mm

For these sharpness tests the Fujifilm XF 18-135mm F3.5-5.6 R LM OIS WR lens was attached to a Fujifilm X-T1 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 35mm

At 35mm the centre is quite sharp wide open, with peak performance achieved in the f/5.6-f/11 range. Diffraction sets in at around f/16, with its effects becoming more visible at f/22.

The edges are somewhat soft at f/4.3-f/5.6 but sharpen up very nicely at f/8, with f/11 the optimum setting.

Aperture	Centre Crop	Edge Crop
f/4.3
f/5.6
f/8
f/11
f/16
f/22