By now I have been using the Zeiss Otus lenses for years. And I consider the Zeiss Zeiss 135mm f/2 Apo Sonnar T* ZF.2 Lens an Otus, even if it was just the pre-cursor. And despite contrary opinions, of the four Otus lenses (135mm, 55mm, 85mm, and 28mm), the 135mm (in my work and opinion) is the sharpest of the bunch. Here is a single shot at f/13 on the Nikon D810 of my favorite indoor wintertime flower, the Cyclamen.