From build quality to optics, the Panasonic Leica 15mm f/1.7 lens over-delivers in a compact 30mm equivalent package.
I am quite pleased with this lens' compactness and image quality. Even wide open at f/1.7 it delivers solid results, albeit a little soft in the corners at this aperture, it sharpens up throughout at f/2.8-4.0 and vignetting is virtually eliminated in the corners.
Build quality is excellent, mostly metal, with this option being the only one of two Panasonic lenses to sport a manual aperture ring (the other being the Leica DG Nocticron 42.5mm f/1.2).
Autofocus is blazing fast on my Panasonic GX7 Mk.II and the motor is almost dead silent.
One quibble I have is that the Leica Summilux name usually stands for an aperture of f/1.4, so I'm not quite sure why Panasonic decided on an aperture of f/1.7 (I'm guessing mostly for the sake of compactness and portability).
Overall, however, this lens is a brilliant addition to any kit, small enough to fit in your pocket and be a discrete, sharp and bright lens you'll enjoy using.
Offt The Fork International