This series evaluates the Sigma 70mm f/2.8 DG Macro from f/2.8 through f/8 on an extremely demanding target: a planar subject with exceedingly fine detail. This target is among the most demanding any lens can face, inexorably showing most all lens weaknesses.
Of keen interest here is focus shift, which is the kiss of death on a ~40MP sensor, let alone a 60MP sensor. When it happens in the central area of the frame, it is a serious problem.
Includes images from f/2.8 to f/8 at up to full camera resolution.