IN THE LAB: SQF sharpness tests produced, as expected, Excellent-range results. DxO's Analyzer Version 3.2 tests found barrel distortion in the low visible range (0.44%) at 16mm, and pincushion distortion in the Imperceptible (0.09%) and Slight (0.22%) ranges at 24mm and 35mm, respectively. Historically fine numbers, but compared to today's high-speed-pro-ultra wides, about average. Vignetting left the corners by f/5 at 16mm, by f/5.6 at 24mm, and by f/4 at 35mm—also average performances. The lens' magnifying power is a forte: At the uniform close focus of 10.35 inches, it ranges from 1:7.45 at 16mm to a considerable 1:3.63 at 35mm.