Very fine detail is clearly rendered with a bit soft edges and extremely fine details are a bit fuzzy and start to overlap each other. In the field fine detail is quite crisply rendered and extremely fine detail is just detectable. The corners show a drop in micro contrast and produce fuzzy detail. Slight barrel distortion and a bit vignetting can be noted. Astigmatism is very well controlled.
Performance holds up to and including the macro position.
Centering is perfect. The lens is very smooth to operate. The only hassle I have with this lens on the R8 is the relatively low brightness of the screen. Given the use of this lens in mostly brightly lit situations a small nuisance. Handling is intuitive and fast.