Typical of the Sigma’s Contemporary lenses, this 18-200mm is designed to be small, lightweight and stylish. Despite matching Canon’s much heftier lens for zoom range, the Sigma measures a mere 71x86mm, making it the smallest in the group, and the second lightest at 430g.
Despite the lightness in weight, the lens features a metal mounting plate, unlike the plastic mount of the directly competing Tamron, although the Sigma omits a weather-seal ring. As in the larger Sigma lens on test, the focus ring rotates during autofocus, but the ring is small and positioned right at the forward end of the barrel, so handling isn’t impaired too drastically. As usual with ultrasonic motor-driven autofocus systems, there’s no full-time manual override.
The Sigma is based on 16 optical elements, with multiple aspherical…
