Sharpness at 50mm

For this test, the Tamron 28-50mm F2.8 Di III VXD G2 lens was attached to a Sony Alpha A7 IV 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 50mm

Center sharpness is outstanding between f/2.8 and f/11. At f/16 and especially f/22 sharpness drops off a little due to diffraction.

Edge sharpness is almost as good as in the centre, with the sharpest results between f/4 and f/11.

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