On the optical bench, Version II showed its mettle, outperforming its predecessor in overall sharpness and contrast, especially at 150mm. SQF numbers were in the mid-Excellent range at the three tested focal lengths, whereas Version I delivered sharpness at 150mm only in the Very Good range. By relatively slight margins, it also bested the Tokina 50-135mm f/2.8 at two out of three focal lengths. Our remaining lab tests revealed overall satisfactory performance and insignificant differences with its rival. DxO Analyzer Version 3.0.1 tests of distortion control, for example, uncovered Imperceptible-range barrel distortion at 50mm (0.10%), and Slight pincushioning at 100mm (0.15%) and 150mm (0.21%)-a state-of-the-art showing. Light falloff was gone from the corners by f/3.5 at 50mm, f/4 at 100mm, and f/5 at 150mm. That's slightly less impressive than the (almost) falloff-free Tokina and a virtual match to Sigma's original version. Magnification ratios at a uniform close-focusing distance of approximately 34.9 inches came in at 1:13.38 at 50mm, 1:6.69 at 100mm, and a merely adequate 1:4.82 at 150mm.