"The Pentax HD DA 18-50mm F4-5.6 DC WR RE, designed for use with Pentax K-mount lens-interchangeable digital cameras. This standard zoom lens features a newly developed retractable mechanism for easy storage and outstanding portability, as well as a weather-resistant construction for dependable operation under all shooting conditions. This standard zoom lens has been developed as a compact, easy-to-use everyday lens that meets user demand for a downsized, high-resolution digital SLR imaging system. Thanks to its retractable mechanism - employed for the first time in the Pentax K-mount lens system - it provides the world's shortest length in the stored position: just 41 millimeters. Despite its ultra-compact design that assures outstanding portability, it also features the Pentax-original HD Coating, super-low dispersion glass elements and aspherical elements to effectively compensate various aberrations for sharp, high-contrast, well-balanced images. Its built-in DC motor assures smooth, quiet autofocus operation, while its weather-resistant body makes it extremely dependable and durable in demanding outdoor conditions. World's shortest standard zoom lens This standard zoom lens offers a zoom ratio of approximately 2.8 times to cover the wide-angle to standard ranges (for focal lengths equivalent to 27.5mm to 76.5mm in the 35mm format), which are the most frequently used ranges in general photographic applications. Thanks to its new retractable me"