Is the Tokina 11-16mm f/2.8 AT-X Pro DX II Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 16mm f/2.8 test image. Observe the contrast and resolution of these results.
Is the Tokina 11-16mm f/2.8 AT-X Pro DX II Lens set to 16mm f/2.8 sharper than the Tokina 11-20mm f/2.8 AT-X Pro DX Lens set to 14mm f/3.2? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.