• Specifications 
• Focal length                          50-150mm
• Aperture                               f/2.8
• Angle of view                        27.9-9.5° (SD Format)
• Filter size / type                    67mm
• Construction                         18/14 Elements/groups
•  Focusing type                       Internal HSM
• Closest focus                         1.0m
• Weight                                 0.77kg
• Dimensions                          76.3x135mm (Dia x length)
•  Mounts available                  Sigma SA, Canon, Nikon (D)
• Tripod bush                           No
• Price (SRP)                           £549.99

Sigma 50-150mm f/2.8 EX DC HSM

The lens retains the same length as you work through both the zoom range as well as the focus variation, which will focus down to a handy one metre. The HSM motor powering the autofocus has evolved to a stage where it is both fast and silent. The lens is supplied with a simple, shallow cone hood that is a positive bayonet fit around the 67mm filter thread.

Fairly compact for a constant f/2.8 lens, this is the first real example of the idea that APS-C only lenses are likely to be smaller than their old 35mm counterparts. Although there is no direct comparison available, this lens approximately covers the same angles of view that a 70-210mm lens would have done on 35mm film. (75-225mm on a 1.5x crop) and proved to be a popular second lens.

With an almost completely uniform profile, with just the hood being slightly wider, and a pair of equal sized rings for the focus and zoom operations, the handling of this optic is quite natural and, as we have come to expect from the EX range, torque to both of them is just right, not being too stiff, but neither too loose. Zoom graduations are marked at 50, 70, 100 and 150mm and there is a distance window marked in metres and feet.

We have come to expect quite good quality from Sigma’s EX range of lenses of late, and there are no real disappointments with this offering. The resolution at the wider end of the zoom range is excellent and this only deteriorates slightly as the lens is pushed out to its longest focal length, a phenomenon that is quite normal. At the widest aperture of f/2.8 it is slightly more noticeable, but only in comparison to the excellent performance it gives at the short end when used wide open.

Chromatic aberrations, the bane of digital photographers, is so well controlled in the centre of the optic that it is virtually immeasurable, even with the Imatest™ software and does not reach proportions that would cause concern even at the edges.

Colour control is neutral and contrast, aided by the digital coating, is good to excellent.