Sigma 18-200mm F3.5-6.3 DC Macro OS HSM C Canon mount lens review: Worthy upgrade?By Kevin Carter - Friday March 28 2014 Lens Review
Sigma 18-200mm F3.5-6.3 DC Macro OS HSM C vs Canon EF-S 28-200mm f3.5-5.6 IS Canon vs Tamron AF 18-270mm F/3.5-6.3 Di II VC LD Aspherical [IF] Macro
Canon users will no doubt contemplate the firm’s stabilized EF-S 18-200mm model and for good reason as it’s not a bad performer. Peak sharpness is a little low by comparison, but the Canon offsets to a degree this by having pretty good center sharpness wide-open at 200mm.
It is also marginally faster at 6.5TStops, versus the Sigma’s 7.2TStops. To the Canon model’s detriment, it has higher barrel distortion, heavier vignetting and some troubling lateral chromatic aberration, but the latter is restricted to the 50-135mm range.
Tamron’s latest 16-element PZD (Piezo Drive) version of the stabilized 18-270mm is a promising option with its longer reach and equally small size. Not only that, but the price is quite modest at $449. It has similar sharpness to the earlier Sigma model but they’ve leapfrogged Tamron, particularly with regard to peak sharpness generally and center sharpness specifically wide-open at 200mm. Although the Tamron has similar transmission, distortion and vignetting the Sigma has lower levels of CA at 200mm, however the Tamron has practically no CA at 18mm.