Leica’s Flat and Fast Panasonic Pancake Lens | Gadget Lab | Wired.com:
Leica shows just how small a lens can be, if you have a camera with a half-sized sensor and no big mirror-flipping gap between it and the lens itself. This is the new LUMIX G 20mm ƒ1.7 ASPH, and it aptly belongs to the class of lenses called “pancake”.