Sigma 18 - 200 mm F3.5 - F6.3 DC lens, is designed specifically for digital SLR's with APS-C sized sensors (1.6x FOV crop ), these are smaller and lighter than the equivalent 35 mm lens as they don't need to produce such as large an imaging circle. This new eleven times zoom lens although a little slow at telephoto (F6.3) would offer an impressive 28 - 320 mm equiv. on a 1.6x FOV crop camera (such as the Canon EOS 700D
62 mm Ø