Each lens was tested at its widest and longest focal lengths and with various apertures using Aperture Priority mode. The crops are taken from the lower left corner of the chart and presented here at 100%. The wide angle crops show a larger area of the chart because the minimum focusing distances forced us to shoot from further away. No crops have been resized.

Zoomed-into 40mm and focused at close range, the 17-40mm delivers very good corner sharpness, compared to the other lenses here, but as seen on our Outdoor results page, the lens becomes quite soft at the extremes when zoomed-in and focused to infinity. It’s clearly important to consider all of our results pages to build a complete evaluation of the lens under different conditions.