Sigma 18-200mm f3.5-6.3 DC Lens

The Sigma 18-200mm f/3.5-6.3 DC lens is specially optimized for digital SLR cameras, and offers an "all-in-one" super-zoom lens solution. 
It's design incorporates aspherical lenses and SLD (Special Low Dispersion) glass that provides the utmost correction for all types of aberrations and enables this extended super-zoom lens to be housed in a compact and lightweight construction.
DC lenses are exclusively designed for digital SLR cameras. The image circle (rear of lens) is made to match the smaller dimensions used for the image sensor on digital cameras. As a result these lenses are also more compact and lightweight, and are better matched to digital SLR cameras. 

Key Features
- Two Special Low Dispersion (SLD) glass elements and two hybrid aspherical lenses offer optimal correction for all aberrations and permit compact, lightweight design. 
- The new lens coating reduces the flaring and ghosting common to digital cameras and creates an optimum color balance. 
- Sigma 18-200 DC incorporates inner focusing, which prevents the front of the lens from rotating, making this an excellent digital SLR zoom lens for using circular polarizing filters and petal shaped lens hoods. 
- The overall length of the Sigma 18-200 DC lens does not change during focusing, ensuring convenient handling and ease of use. 
- Zoom lock switch eliminating zoom creep during transportation, for convenience when traveling.