Resolution (f16)

Nikon 17-35mm 2.8 v Zeiss 21mm 2.8 v Canon 17-40mm f4 L

21mm at f16 (Zone A)
nikon 17-35 at f16: Zone A Canon 17-40mm at 21mm/f26: Zone A Contax 21mm at f16: Zone A
Nikon 17-35mm

at 21mm / f16 (centre)

Canon 17-40mm

at 21mm / f16 (centre)

Zeiss Contax 21mm

at f16 (centre)

4.7 points
4.7 points
4.8 points

All lenses are now clearly diffraction-limited in their resolving powers, but again the Zeiss has a little extra magic and sparkle thanks to its ‘drawing’ style.

Performance at f16 (Zone B: Left Side)

nikon 17-35 at f16: Zone B Canon 17-40L at 21mm/f26: Zone B ff
Nikon 17-35mm

at 21mm / f16 (mid-frame)

Canon 17-40mm

at 21mm / f16 (mid-frame)

Zeiss Contax 21mm

at f16 (mid-frame)

4.6 points
4.7 points
4.8 points

The Canon 17-40mm L here gets a little payback for its absence at f2.8: across the frame it’s a little better than the Nikon 17-35mm f2.8.

Performance at f16 (Zone C: Near Field)

nikon 17-35 at f16: Zone C Canon 17-40mm at 21mm/f26: Zone C ff
Nikon 17-35mm

at 21mm / f16 (corner)

Canon 17-40mm

at 21mm / f16 (corner)

Zeiss Contax 21mm

at f16 (corner)

4.4 points
4.6 points
4.8 points

. . . especially in the near-field , where it has been outperforming the Nikon for about a stop now.