Sigma 24-105mm F4 DG OS HSM A Canon mount lens review: A new standard?By Kevin Carter - Monday December 16 2013 Lens Review
The new Sigma achieves a DxOMark lens score of 24 points on the 22-Mpix Canon EOS 5D Mk III, and has a very high sharpness score of 18P-Mpix, one of the sharpest in the professional zoom category. Sharpness is good in center but corner sharpness is noticeably lower throughout the zoom range and aperture settings. Nevertheless the overall performance puts it in joint third place in our rankings for those lenses, just ahead of Canon’s previous EF 24-70mm f2.8L USM and Sigma’s current 24-70mm f2.8 model.
More importantly perhaps, it’s also ahead of the Canon 24-105mm f4L IS USM, which is ranked seventh and the EF24-70 f4L IS USM ranked sixth. However, at maximum aperture, vignetting is quite strong between the 70 to 105mm focal lengths and chromatic aberration, while low for this type of lens, may be visible at either ends of the zoom range. Barrel distortion is slightly higher than average and it quickly turns to pincushion at 35mm.