This compact mid-telephoto lens uses AD (anomalous-dispersion) glass elements to provide apochromatic correction. It produces images with excellent color balance and sharpness from 4.9' to infinity, while its internal focusing system provides high-speed autofocus. This lens comes with a protective front filter and a focus-hold button conveniently located on the side of the lens barrel, and adjusting the focusing range is easily done using the focusing range ring.