As a more modestly priced alternative to the EF 2470mm f28L II USM and with a longer reach than the newer stabilized EF 2470mm f4L IS USM, the similarly stabilized EF mm f4L IS USM remains a popular model for Canon usersAs a new addition to the Artseries, the Sigma mm f4 DG OS HAS looks promising, but can the firm replicate the image quality of their recent 35mm f14 and 18Sigma mm f/4 DG OS HSMA review Image quality Image At its best, the lens resolves lots of detail across almost all the frame This was shot at 24mm and f/8 Optically, the Sigma mm f/4 lens is a pretty capable performer When shot wide open, the corners of the image are a little soft, but the lens is impressively sharp acrossSigma 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 surprise Firstly nobody expected Sigma would dare enter a segment so clearly dominated by Canon and Nikon instruments Sigma 24 105mm F4 A Dg Os H