Review by Markus Stamm, published December 2009

Introduction

The only third party company confident enough to offer a lower cost alternative solution was and still is Sigma, who overhauled the 24-70/2.8 EX lens and as one of the main new features added a HSM drive (finally!). The non-HSM lens remains in Sigma's portfolio, at least for now.

Unlike the Nikkor 24-70, the Canon 24-70L and its older non-HSM sister the Sigma HSM lens is a more "traditional" zoom lens, shortest at its 24mm setting with one inner lens tube extending towards the tele end. At least at its wide angle setting the lens feels way more compact than the Canon and Nikon lenses with their huge hoods, but noticeably thicker.

The build quality is excellent, zoom and focus ring are damped and operate smoothly, there's no wobbling and the lens features the well known EX crinkle finish. It is not dust or weather sealed, though. The tested sample showed no signs of zoom creeping.

Zoom and focus ring work in "Canon style" which is the opposite direction of Nikkor lenses. Someone using mainly Nikon glass might need some time to get used to it and override his or her muscle memory. This is of course no issue with the EF-mount version of the Sigma lens, any Canon shooter should feel right at home here.

Thanks to an IF (internal focusing) design the front element does not rotate so using a polarizer is no problem. However, because of a fairly large filter diameter (82 mm) which this lens inherits from its predecessor, a polarizer, especially a higher quality one, easily becomes a rather expensive accessory. Like all Sigma HSM lenses the 24-70 EX features a silent-wave (ultrasonic) AF motor providing extremely fast and near-silent AF operations and manual focus override at any time. Like most modern F-mount lenses it does not feature an aperture ring (a G-type lens).