Review on Tokina 17 35Mm AT X Lens Canon by Micael Rau

I calibrate all my lenses using the Reikan FoCal software which sets the micro focus on cameras that support it, both Canon 70D and 6D and this is the first example of this lens that I have just bought have not been calibrated to 35mm on any of the cameras - all test points tested by the software failed to get consistent readings at any setting, even after extensive testing. The only time I've had this problem with another lens was with an old Canon lens that was later found defective by the manufacturer's customer service. Sharpness values are achieved surprisingly well with an open aperture of f4. Thinking I might have a bad copy I sent the 1st lens back and ordered the 2nd which the software was able to easily calibrate to 35mm, although it required a high adjustment factor -- +11 on 6D and +14 on 70D. As with the first lens, the 17mm end was easy to calibrate with a minimum correction of -1 on the 6D and +3 on the 70D. Sharpness was again best at f4 wide open. Verdict: The wide-angle lens on this lens does a great job and is stable. However, its maximum focal length proved unsuitable for one of the copies I tested, requiring a significant adjustment to calibrate the other copy. I will keep a second copy as I have other longer focal length lenses (I bought this specifically for the wide angle lens) but I would consider other options if you need something with consistent quality throughout the zoom range.