Is the Zeiss 100mm f/2 Makro Classic Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 100mm f/4.0 test image. Observe the contrast and resolution of these results.
Is the Zeiss 100mm f/2 Makro Classic Lens set to 100mm f/4.0 sharper than the Zeiss 100mm f/2 Makro Classic Lens set to 100mm f/11.0? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.