Sigma has release an 18-35mm f/1.8 constant aperture zoom lens designed for DSLRs with APS-C sized sensors. And the new zoom lens is the world’s first zoom len to achieve a maximum aperture of f/1.8 throughout its zoom range. The new lens fits into Sigma's...
… The World’s first f/1.8 Constant Aperture from Sigma
Thursday, April 18 2013