Zeiss 35mm ƒ/1.4 Distagon Focus Study

How sharp is the Zeiss 35mm ƒ/1.4 Distagon at ƒ/1.4? Very sharp, but perfect focus is demanded to achieve it (as with all fast lenses).

Just published in my Zeiss Guide is a study at ƒ/1.4 of two images with the Zeiss 35/1.4 Distagon, one focused optimally, and one barely different in focus (in terms of the focusing ring)— but very different in results.

Hoover Wilderness high alpine lake
Nikon D3x + Zeiss 35mm ƒ/1.4 Distagon @ ƒ/1.4, 1/8000 sec, ISO 80