This fast tele incorporates new XD (extreme dynamic) Linear Motors that deliver higher thrust than conventional motors in current and future camera bodies. Newly designed algorithms quietly drive the lens’s large focus group for capture of fast-moving sports and wildlife subjects. The lens incorporates three fluorite elements to minimize chromatic aberration, with spherical aberration controlled through rigorous design and manufacture quality, even with the use of Sony’s high-performance 1.4X and 2.0X teleconverters. The optical design reduces the number of elements at the front of the barrel, and durable magnesium alloy components result in a low weight of 2897 grams.