Tokina AT-X 17-35mm f/4 Pro FX - unknown Mount

The AT-X 17-35mm f/4 Pro FX is a wide-angle zoom designed specifically for full-frame DSLR cameras. It offers a practical focal range for landscapes and photojournalism with a constant f/4 aperture. The lens is engineered to be more compact and lightweight than f/2.8 equivalents, while still maintaining a robust, moisture-resistant build. It features two super-low dispersion glass elements and one aspheric glass element to manage distortion and chromatic aberration. When inspecting a used 17-35mm, check the weather sealing gaskets at the mount for any signs of perishing. SDS verifies the quietness and speed of the AF motor and ensures the focus clutch operates correctly. We also look for optical clarity, specifically checking for any signs of coating degradation on the front element. The zoom action should be consistent across the range without any tight spots or rattling.