The lens features an optical image stabilizer that allows for shake-free images in virtually any situation. The narrow field of view dramatically compresses perspective and allows for flexible background composition. The focused area remains impressively sharp and clear. Although telephoto lenses are usually large and heavy, Sigma offers a practical, easily transportable zoom lens with the 100-400 mm F5-6.3 DG OS HSM. The combination of excellent optical performance and compact design makes this ultra-telephoto zoom lens a truly special companion.