Sharpness at 100mm

For these sharpness tests the Fujifilm XF 55-200mm F3.5-4.8 R LM OIS lens was attached to a Fujifilm X-Pro1 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 100mm

At 100mm the centre is slightly soft wide open, with peak performance achieved in the f/5.6-8 range. Diffraction sets in at around f/16, with its effects becoming more visible at f/22.

The edges are somewhat soft at f/4-5.6 but sharpen up very nicely at f/8, with f/11 the optimum setting.

Aperture	centre Crop	edge Crop
f/4
f/5.6
f/8
f/11
f/16
f/22