Sharpness at 24mm

The sharpness tests for this review were carried out using a real-world subject rather than a test chart. The Sigma 24mm F2 DG DN lens was attached to a Sony A7 III camera body, which in turn was mounted on a sturdy tripod. Self-timer mode was activated. Slight tonal changes are due to slight changes in natural light during the session.

The full frame at 24mm

The centre is very sharp even when shooting wide open, so you can happily use f/2-f/11. Diffraction sets in at at f/16 and especially f/22.

The edges aren't quite as sharp as the centre, being just a little soft at f/2, with f/4-f/11 the optimum settings.

Aperture	Centre Crop	Edge Crop
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16
f/22