At full aperture, image quality at 10mm is quite good right in the center of the frame - not exactly crisp, but fairly good levels of detail are recorded. Moving towards the corners, things get softer though - About the central two thirds of the image is reasonably sharp, with a noticeable fall in resolution as you move right in to the corners. Results at 13mm are very similar, while at 17mm the image gets softer still - Even central details have a slightly soft focus look to them. Overall, full aperture performance is OK at 10-13mm, poor at 17mm.

Stopping down to f5.6 improves results markedly - especially at 17mm where the center field is now quite sharp, only the corners still look a bit soft. Another stop fixes even that, with good sharpness, right through the range even in to the corners. This is an extreme lens - at 10mm it’s field of view is 180 degrees, so poor corner performance at wide apertures isn’t unusual, but it’s at 17mm that this lens is at it’s weakest. Vignetting is hard to judge with a lens like this - it’s not noticeable in any of the test frames.

Stopped down to f5.6 or f8 this lens is capable of very good results, with very high levels of sharpness in the center of the frame. Flare - often a big problem with such a wide angle lens - doesn’t seem an issue with the Tokina 10-17 which has a built in lens hood and uses a new ÅgWater ProofÅh lens coating. All fisheye lenses need to be used with extreme care, and this lens has the advantage of being a zoom which should allow very accurate cropping of images for maximum effect.