AP review of the Panasonic S 50mm f/1.8
Amateur Photographer tested the Panasonic S 50mm f/1.8 and concluded:
The Lumix S 50mm F1.8 falls more into the first camp. It’s not exactly bargain-basement-priced, but it’s affordable and its f/1.8 aperture delivers the speed we crave. It’s lacking some of the refinements that we see on other lenses such as a focus limiter switch, a customisable function button or a control ring that can be used to adjust aperture or exposure compensation, but it’s weather-sealed, feels well-made and comes with a good, deep lens hood. Most importantly, it delivers extremely good quality images with no curvilinear distortion, next to no vignetting, just the occasional issue with fringing (which is correctable) and an impressive ability to maintain sharpness right into the corners.
With a lens this good, you’d really have to need the extra 1/3EV in aperture size to be willing to pay five times more to get the Lumix S Pro 50mm F1.4.