Tokina Wide Angle Lens for Canon Camera

Tokina atx-i 11-16mm f/2.8 CF Lens for Canon EF. EF-Mount Lens/APS-C Format 17.6-25.6mm (35mm Equivalent) Aperture Range: f/2.8 to f/22 Two Aspherical Elements Two SD Low Dispersion Elements Multi-Coated Elements One-Touch Focus Clutch Mechanism Internal Focusing Design 9-Blade Diaphragm Bought new in March, used only 3 times before deciding to upgrade my camera, and this lens no longer works with my new set up.