The Sigma 18-50mm F/2.8 DC D EX is ideal for cameras with APS-C sensors. The Sigms 18-50mm is a relatively quiet, compact, and lightweight zoom lens. This lens has minimum focus distance of 0.2m and employs a .2x magnification factor. The internal focusing does not change the length during focusing and the front elements does not rotate. SLD glass elements help eliminate chromatic aberrations while providing superb image quality throughout the zoom range. Super Multi Coating on the glass minimizes flare and ghosting and ensures high contrast images.The EX lens series signifies excellence of engineering and new technology.