Sharpness at 50mm

For this test, the Sony Carl Zeiss Planar T* 50mm F1.4 ZA SSM lens was attached to a Sony A99 body, which in turn was mounted on a sturdy tripod. Exposure delay mode was activated. Tonal and colour variances across the crops are due to changes in natural light during the session.

The full frame at 50mm

Centre sharpness remains high through from f2 to f/16, with f/1.4 a little soft and f/22 being adversely affected by diffraction. The edges aren't quite as sharp as the centre, with f2.8-16 producing the sharpest results.

Aperture	Centre Crop	Edge Crop
f/1.4
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16
f/22