Tamron SP AF 28-75mm f/2.8 XR Di LD - £355
At little more than half the weight of the Canon EF 24-70mm full-frame lens, this one is also much more compact and only about a third of the price. Despite this, it features a fast, constant f/2.8 aperture and, like the Canon, lacks image stabilisation.
It's a sign of market forces that Tamron felt the need to update the 17-50mm APS-C version of this lens to fit Vibration Correction, but didn't do so with the full-frame 28-75mm.
Vignetting is very pronounced on full-frame cameras but the crop factor of APS-C bodies bypasses the problem. Fitting the lens to APS-C bodies also masks a lack of sharpness at the corners of the frame, especially when using large apertures of f/2.8 to f/4.
However, on cameras such as the Canon EOS 600D and 60D, the effective zoom range of 45-120mm really does lack any wide-angle potential. Indeed, the widest effective focal length is much closer to the 50mm of a 'standard' prime lens.
All things considered, it's not a particularly good lens for full-frame cameras and far from an ideal performer on an APS-C camera. For the latter, Tamron's 17-50mm f/2.8 VC is even less expensive and a much better buy.