|Introduction | Sigma 24-70mm f2.8 IF EX DG HSM lens performance | Sigma 24-70mm f2.8 IF EX DG HSM versus Sony Vario-Sonnar T* 24-70mm f2.8 ZA SSM versus Tamron SP AF 28-75mm f2.8 XR Di LD Aspherical [IF] | Conclusion|
A peak sharpness score of 15P-Mpix is very good, but sharpness at maximum aperture is variable throughout the zoom range. Sharpness is much better at 24 and 28mm than it is at the longer end, at least in the centers but corner sharpness wide-open is poor.
Stopping down to f4 improves uniformity at the wider end and enhances center sharpness at the other – in effect the longer end is stops behind. Distortion is noticeable at either end and is vignetting, but it’s very low between the 35mm and 50mm range. Lateral chromatic aberration is somewhat troubling, however; it’s particularly evident in periphery at the wide-end (24-28mm) and it’s noticeable regardless of the aperture value.