The Sigma 28-70mm f/2.8 EX DG Lens features a fast, fixed 9-blade aperture ranging from f/2.8 to f/22. Again, you probably will want to avoid f/2.8 over most of the focal length range. A 67mm filter diameter keeps the Sigma 28-70's objective end reasonably small. Not many lenses share this filter diameter (the Canon EF 70-200mm f/4 L USM Lens
Canon's update to its professional fast telezoom may look much the same on the outside, but internally it's been updated to give image quality that's quite simply the best in its class. Effective autofocus and image stabilization systems, plus full weather sealing, round off a compelling package. Lens reviews update: 70-200mm lenses added to
As an L-class lens with Canon's USM focusing technology, there aren't many lenses which will keep up with the focusing speed of the EF 70-200mm ƒ/2.8L IS II USM. It takes well less than a second The Sigma 17-70mm f/2.8-4 DC Macro OS Lens features a great general purpose focal length range, short minimum focus distance, HSM autofocus and OS (optical stabilization) in a well-built and very affordable lens. Its image quality is not all I hoped for. The 17-70mm focal length range very comfortably covers the recommended general purpose lens The Canon EF 24-70mm f/2.8 USM L is an impressive zoom lens upon first contact but it stayed somewhat short of the high expectations with respect to its optical characteristics. It can certainly produce sharp images if you know how to handle it but the pronounced field curvature at the wide end is a faux-pas which can often spoil the game. nVNAF.