At 55mm, sharpness in the centre of the frame at maximum aperture is already outstanding, with the clarity towards the edges falling just short of excellent. Stopping down to between f/4 and f/8 raises sharpness towards the edges to excellent levels, whilst maintaining outstanding clarity in the centre of the frame. Zooming to 100mm results in an overall reduction in sharpness across the frame. Still, sharpness is very good in the centre of the frame at maximum aperture and good towards the edges of the frame. Peak sharpness is achieved with the aperture stopped down to f/8 for this focal length. Here clarity is excellent across the frame. Finally, at 200mm there is a further, slight reduction in clarity. At maximum aperture, sharpness approaches very good in the centre of the frame and is good towards the edges of the frame. Peak sharpness is again achieved at f/8. Here clarity in the centre falls just short of excellent and is very good towards the edges of the frame.