Sharpness at 200mm

For this review, the sharpness test is carried out by photographing a real-world sample, rather than a test chart. The Canon EF 70-300mm f/4-5.6 IS II USM Lens was mounted on a Canon EOS 5D Mark IV, which was in-turn mounted to a sturdy tripod. Exposure delay mode was activated to prevent camera-shake. Any changes in tone you might see across the crops are due to natural light changes during the shooting session.

The full frame at 200mm

For the 200mm focal length, it is very sharp between the widest aperture (f/5.6) and f/16. Images start to become softer from f/22 onwards, being at their softest at the narrowest aperture of f/45. When it comes to the edges, the sharpest images are taken at f/16 and f/22.

Aperture	Centre Crop	Edge Crop
f/5.6
f/8
f/11
f/16
f/22
f/32
f/45