Optical Stabilization (OS) provides compensation for camera movement and delivers clear, blur-free images when shooting telephoto and in low light. A Special Low Dispersion Glass element and three aspherical elements, including one double-sided aspherical lens, reduce chromatic aberration and provide sharp imaging throughout the zoom range. Super Multi-layer Lens Coating reduces flare and ghosting and an included petal-type lens hood will deflect unwanted light from entering the lens. A Hyper Sonic Motor (HSM) allows for smooth and silent autofocus which is particularly desirable when shooting video with your DSLR.
At 3.5" (8.9 cm) long, it is a very compact lens for its wide focal range and Thermally Stable Composite (TSC) construction and a brass mount offer durability and consistent functionality in varying temperatures and situations.
The Sigma EF610 DG ST Flash for Pentax is a hot-shoe mount flash unit with TTL automatic flash exposure and an auto zoom function that adjusts the flash angle based on the chosen focal length of the lens (from 24-105mm). A built-in wide panel extends the flash angle to 17mm for wide-angle shooting. Manual control is also available to control the flash power from full to 1/16 power. The Guide Number for the EF610 is 61 m at ISO 100 and 105mm.
The flash head can be tilted up 90º and down 7º and swivelled 90º to the right and 180º to the left for flexible bounce control.