Sharpness at 21mm

Our sharpness tests were conducted using a 50-megapixel Canon EOS 5DS R body mounted to a tripod. The camera's shutter release was also set on a timer-delay to avoid any possible camera shake. The test subject was shot using ambient lighting, hence some colour and contrast variation is to be expected between apertures.

The full frame at 21mm

Centre sharpness is high right throughout the entire aperture range, with peak performance between f/4-f/11. F/16 and f/22 are marred slightly by diffraction. At the edges, peak performance is again achieved between f/4-f/11.

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