The lab tests reveal varied image quality characteristics in these wide-angle lenses. Lenses tested on the Canon EOS 7D (the Canon EF-S 10-22mm f/3.5-4.5 USM, Tamron SP AF 10-24mm f/3.5-4.5 Di II, Sigma 8-16mm f/4.5-5.6 DC HSM and Sigma 10-20mm f/3.5 EX DC HSM) resolved less sharp detail from JPEG images.
Those tested on the Nikon, Olympus or Sony cameras (the Nikon AF-S DX 10-24mm f/3.5-4.5G ED, Olympus Zuiko Digital ED 9-18mm f/4-5.6, Sony DT 11-18mm f/4.5-5.6 and Tokina 12-24mm f/4 AT-X 124 AF PRO DX II) resolved more. Also, the results are more uniform across the focal range than the other makes.
The Tamron and Canon lenses also delivered consistent results. At their widest focal lengths all lenses had typical wide-angled characteristics, with sharpness falling towards the edges of the frame. The Nikon optic showed most barrel distortion at its widest focal length, followed by the Sigma 8-16mm.
Most lenses showed pinch distortion at the narrowest focal length, but the Sony and Tamron optics retained mild barrel distortion throughout.
Fringing for all lenses at the centre of the frame was minimal, but the Sony lens displayed visible signs towards the edge.
Overall, the Nikon lens just takes the lead for consistency.