DPReview posted a real-world sample gallery shot with Sigma’s latest marvel, the Sigma 50-100mm f/1.8 DC HSM Art lens. What so special with this lens (and with the awesome Sigma 18-35mm f/1.8?). It’s the following:
Sigma’s F1.8 zooms for APS-C are ground-breaking in the following sense: F1.8 on APS-C gives you around the depth-of-field control of F2.7 on full-frame. That makes Sigma’s 18-35/1.8 and 50-100/1.8 roughly equivalent to 27-53/2.7 and 75-150/2.7 lenses on full-frame, in terms of both DOF and noise (in low light) control […]. For some, these lenses go a long way in addressing some of the inherent disadvantages of the smaller sensor format.