The Panasonic 20mm f1.7 is a compact pancake lens that gives users a bright f1.7 normal range lens. The versatile 20mm focal length (40mm after sensor crop) is designed to work great in all applications, from landscape to indoor available light shooting. It’s small size pairs great with the current crop of micro 4/3 cameras. Despite its tiny size, the lens has 7 elements in 5 groups and a 7 curved blade aperture system, making sharp images and smooth out-of-focus highlights.
Panasonic camera bodies automatically correct for lens distortion when this lens is mounted (Olympus bodies do not), so the lens will function better on a Panasonic body. It does exhibit some barrel distortion and chromatic aberration when shot on other cameras. But, overall, it’s remarkably good for a lens this tiny, better than the zooms most people shoot on Micro 4/3 cameras.