Sharpness at 300mm

For this test, the Fujifilm XF 150-600mm F5.6-8 R LM OIS WR lens was attached to a Fujifilm X-H2S 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 300mm

The centre is pleasingly sharp even wide open at f/6.4, with peak performance achieved in the f/8-f/11 range. Diffraction starts to set in at f/16.

The edges are almost as sharp as the centre, with f/8 to f/11 again the optimum settings.

Aperture	Centre Crop	Edge Crop
f/6.4
f/8
f/11
f/16
f/22