Introduction Introduced late 2005, the Canon EF24-105mm f4L IS USM was intended as the final lens in the maker’s range of smaller, lighter more accessible priced f4 zoom variants, and was a rightly popular model. More recently, Canon added a compact EF24-70mm f4L IS USM model to the series but the extra range together with the constant maximum aperture of the 24-105mm is very appealing, not only for stills but also for filmmakers.Mindful of this potential market, independent lens maker Sigma has introduced a similarly specified constant aperture 24-105mm model complete with four-stop stabilization (as opposed