Tamron 17-70mm F/2.8 Di III-A VC RXD Review
Sharpness at 70mm
Our sharpness tests are carried out by photographing a real-world subject rather than a test chart. The Tamron 17-70mm F/2.8 Di III-A VC RXD was attached to a Sony A6000 camera, which in turn was mounted on a sturdy tripod. Self-timer mode was activated to steady the camera completely. Any slight tonal changes you may see across the crops are a result of slight changes in natural light during the shooting session.
The full frame at 70mm
Centre sharpness at f/2.8-f/4 is a little soft, but it's impressively high through from f/5.6-f/11, with f/16 and f/22 being affected by diffraction.
Although soft wide open, the edges are at least as sharp as the centre, with f/5.6-f/11 again producing the sharpest results.