Photography Blog posted their full review of what is thought to be the world’s sharpest lens, the Zeiss 85mm f/1.4 Otus lens. And they tested it on a Canon EOS 5Ds[/shoplkink].
The Zeiss Otus 85mm f/1.4 Planar T* is simply a superb prime lens for portrait photographers looking for the ultimate in image quality. You’d expect sharpness to be high across both the frame and aperture range from such a premium optic, and it doesn’t disappoint. In conjunction with the new Canon EOS 5Ds test camera shooting at 50 megapixel resolution, detail is exceptionally detailed and sharp. Shooting at the maximum f/1.4 aperture does reveal a minor reduction in sharpness compared to the rest of the aperture range, but the image is already pin-sharp by f/1.8. Read the review at PB.