The macro lenses in our test ranged in focal length between 50mm and 105mm, with all but the Zeiss Makro-Planar T* F2 100mm ZE specifically designed for macro use.
All the lenses have a maximum aperture of f/2.8 – except the Zeiss and the Olympus Zuiko Digital ED 50mm 1:2.0 Macro at f/2 – and a minimum aperture value of between f/22 and f/32.
The lab test results show that all of the lenses perform well for centre sharpness at f/8 and f/16, but at the maximum aperture of f/2.8, the Olympus Zuiko Digital ED 50mm 1:2.0 Macro, Sony 100mm f/2.8 Macro and Pentax smc D-FA 100mm f/2.8 Macro WR lenses all produced visibly softer images, with results considerably lower than those of the other lenses.
The Sigma 105mm f/2.8 EX DG OS HSM, Nikon AF-S VR 105mm f/2.8G IF-ED, Tamron SP AF 90mm F/2.8 Di Macro 1:1 and Zeiss Makro-Planar T* F2 100mm ZE all produce good centre sharpness across the aperture range, with the Sigma and Zeiss really leading the group with sharp results across the entire frame.
As expected from fixed focal-length lenses, the amount of fringing is minimal, with only the Pentax, Nikon and Sony lenses showing mild signs towards the edges of the frame.