This is the second test shot (the first is here).
It may seem crazy to conduct “test shots” on well established Leica lenses, but the last lens I tried was front-focusing by several inches.
In this case, everything looks to be okay:
↑Leica M9 and Leica 28mm Elmarit ASPH @ f/2.8.
100% central crop of above image:
(please click on the image to view at MAXIMUM size and sharpness)
This 100% magnification clearly demonstrates just how sharp this lens is wide open at f/2.8.