hi is dxomark lens best a test accurate? all the lens test is "best at f1.4\f2" wide open. dont most lenses get best sharpness and contrast when stop down more f5.6\f8?
Thanks for your question and your interest in DxOMark. DxOMark score is computed for a challenging use case and takes every image quality aspect into account: noise, dynamic range, sharpness, transmission etc…. For the specific use case chosen, wide apertures have a major role in the limitation of noise. When sharp enough, lenses perform their best score at f/2 or wider.
The sharpest aperture is not provided in the score sheet but you can check the sharpness map. Most of the time the sharpest apertures are between f/2 and f/5.6 depending on the widest aperture available.
Hope this helps.