This L-series zoom has seals and gaskets against dust and moisture. Our tests found super-sharp optics, but with high distortion numbers.
Standout Spec: Sharpness throughout the focal range, even at its widest
Canon 24-70mm f/2.8L USM AF
Nikon AF-S DX Zoom-Nikkor 10–24mm f/3.5–4.5G ED
SIGMA 24–70mm f/2.8 EX DG HSM
Sigma 12–24mm f/4.5–5.6 EX DG HSM