Sigma 18-200mm F3.5-6.3 DC Macro OS HSM C Canon mount lens review: Worthy upgrade?

Introduction As the equivalent to a 28 to 300mm or thereabouts in 35mm terms, APS-C format 18-200mm zooms have become rightfully popular as a lens for all-round use.  As a consequence of Sigma’s Global Vision strategy this revised version is the latest in a line of lens models from the company dating back to 2005 and features a number of refinements over its stabilized predecessor. Modifications include a reduction in weight and size, whilst maintaining image quality say Sigma.A double-sided aspherical element has helped reduce the weight, as has a new smaller AF actuator. As a