Features a pair of sensors that compensate for camera shake and automatic detection of camera movement when panning...

Excellent resolution for this type of lens; OS; price

Too much chromatic aberration

The pictures below illustrate the focal length range from wide to telephoto (on Nikon DX format, 1.5x).

Huge 11x focal length range; ideal general purpose and travel lens; Relatively low chromatic aberration; Low distortion (for a superzoom; Reasonably effective optical stabilization system; 2.5 - 3 stops benefit

Very inconsistent sharpness through the zoom range - extremely soft at 80mm; Soft corners at all focal lengths; Occasionally indecisive autofocus; Slightly less resistant to flare than its more recent competitors

Unsurprisingly a lens with this kind of focal range is rarely going to perform as well as one with a shorter range, but we were impressed overall by the results possible. Certainly unless you're into extreme wide or telephoto work, or demand the ultimate quality, you could really be very happy with...

Highly versatile 11.1x zoom range; Great value; Relatively small and light - great travel lens; Polariser-friendly internal focusing

Tamron version very similar; Pricier Nikkor version has anti-shake; Pricier Nikkor version is optically faster; Pricier Nikkor version has better build quality

The perfect lens does not exist. There is no lens that covers an extreme range of focal lengths, has an ultra-wide aperture, has incredible build quality but remains small and light, has amazing image quality at all available settings – and is inexpensive.

Although Sigma released their first lens with a built-in Optical Stabilizer (OS) system in the spring of 2004, the company employed this technology in only one pro-grade lens, the 80-400mm f/4.5-5.6. That has changed with the introduction of a more compact/affordable (digital-only) 18-200mm OS zoom.

Sigma continued the miniaturization trend; at the beginning of 2014 they presented another lens of that series, the C 18–200 mm f/3.5–6.3 DC Macro OS HSM. In its case the number of elements decreased from 18 to 16 but the number of low-dispersion and aspherical elements actually increased.

compact dimensions for such a wide focal range; very good image quality in the frame centre across the whole focal range; decent image quality on the edge of the frame; very good correction of the longitudinal chromatic aberration; sensible correction of lateral chromatic aberration; proper...

a bit too many reflections near 100 mm focal length; noticeable vignetting at both ends of focal range; image quality on the edge of the frame at 18 and 100 mm and at the maximum relative aperture a bit under the decency level

Sometimes we are joking about a hypothetical 18-300mm f/1.8 to meet all our photographic needs. Well, we aren't quite there yet nor will we ever see such a lens on a DSLR but the manufacturers are at least scratching this focal length range with some 18-200mm variants and the Sigma AF 18-200mm...

I bought it used in almost new condition. I needed a go around lens to take with me on a 2 weeks trip to Europe. I shoot with Sigma SD14 DSLR and own 6 different lenses by Sigma to go with it. This one easily replaces 3 of them. So I don't have to carry extra weight.

I bought this lens used a couple of years ago and paired it up with a used canon 7d, the total investment for both lens and camera was little less than $600. Overall, this is a very sharp lens. The drive motor is a little noisy but it focuses quite fast even in low light conditions.

Yes, I would recommend this to a friend

Consistent Output; Durable; Rugged

Heavy