There were different wishes, expectations and rumours circulating some wanted it to be a 2470 mm f/ instrument, others expected a 14/24 or a 28/300 OS lens Sigma surprised all of them, even doubly so In the middle of October 13 they announced a presentation of the Sigma A mm f/4 DG OS HSM It was really a huge surpriseThe Sigma mm f/4 DG OS HSM "A" is a highperformance, fullframe, Artseries lens with a constant f/4 aperture and Optical Stabilizer IS system, and competes directly against the CanonThe Sigma 2470mm F28 DG OS HSM Art is an exciting new professional standard zoom lens for fullframe DSLR cameras Retailing for £1399 / $1299, can the Sigma 2470mm f/28 compete with the equivalent lenses from Canon and Nikon? Sigma 24 105mm F 4 Dg Os Hsm A Lens Review Ephotozine Sigma 24-105mm f4 dg os hsm art lens review