Sigma 18-200mm F3.5-6.3 DC Macro OS HSM Review
The Sigma 18-200mm F3.5-6.3 DC Macro OS HSM ($399) is, considering its zoom range, a fairly compact all-in-one lens that's available for Canon, Nikon, Pentax, Sigma, and Sony APS-C cameras. In full-frame terms, it covers a 27-300mm field of view. It can't match the optical quality of a prime lens, or Sigma's much larger and shorter 18-35mm f/1.8 zoom, but images throughout the zoom range are very useable, and sharpen up nicely when the lens is stopped down.
The 18-200mm measures just 3.4 by 2.8 inches (HD), which is quite compact when you consider its zoom range. It does extend when zooming, doubling its height at 200mm, and it's not that light at 15.2 ounces. The front element is static during zoom and focus, so using a polarizing filter is feasible; the lens has a 62mm filter thread. A reversible lens hood is included.
There are two control switches on the lens barrel—one toggles image stabilization (unless it's paired with a Sony or Pentax camera; they have in-body stabiliz...
The Sigma 18-200mm F3.5-6.3 DC Macro OS HSM lens trades some optical quality for a compact design, low cost, and long zoom range.
Long 11.1x zoom range; Compact; Maximum 1:3 macro magnification; Optically stabilized; Compact; Available for most APS-C camera systems; Attractive price tag
Sharpness suffers at maximum aperture; Distortion throughout zoom range