3-Way Shootout: Leica 50mm f/1.4 Summilux-SL ASPH, Panasonic Lumix S PRO 50mm f/1.4, Panasonic Lumix S 24-105mm f/4 (Mosaic)
See my L-mount mirrorless wishlist.
This subject is extremely demanding for lens performance. It is a highly detailed planar target and thus intolerant of focus shift and field curvature, revealing any lens weakness. Examined in this comparison are lens symmetry (e.g., build tolerances), sharpness particularly in outer zones, focus shift (!), field curvature, and total imaging performance.
Includes images at 47 and 93 megapixels, downsampled from the 187MP Multi-Shot High-res mode images, plus crops from the 93 megapixel images, all from f/1.4 through f/8.
This comparison is unusually compelling—recommended reading for all and even if these lenses are not of specific interest.