The EF 50mm f / 1.4 USM is the middle class within the 50 mm fixed focal length lenses from Canon and combines good image quality with small dimensions and low weight. Thanks to its ultrasonic motor can always be manually intervened in the autofocus (without having to switch to MF) however is an older USM generation that does not react as quickly and silently as modern variants, yet very precise. The lens is solid processed though outwardly only the bayonet is made of metal. The excellent full aperture the lens is well suited for available light and portrait shots. Due to the high resolution, it is also used in landscape photography his lover (but not so much to APS-C cameras, where the effective focal length is 80 mm). Even at low aperture value (maximum aperture), the EF 50mm f / 1.4 USM provides an impressive resolution, although fringing ("Chromatic Abber rations") tarnish the result in sharp ("lateral chromatic aberration") and blurred ("longitudinal chromatic aberration") image areas. On full frame cameras and distortion ("distortion") are a problem and a shadow edge ("Vignette") is at least at low F-numbers (maximum aperture) clearly visible. The sharpness level is not curved (as it should be, not a "curvature of field") and the circular shape of the aperture ensures a quiet bokeh (blur of beauty).
Even if the EF 50mm f / 1.4 USM more than three times the cost, as the EF 50mm f / 1.8 II, it is in contrast to the high-end version (the EF 50mm f / 1.2L USM) still affordable for most. The charge you pay for a much better autofocus motor, a better build quality, a properly dimensioned focus ring and of course for the slightly better maximum aperture of f / 1.4 instead of f / 1.8. In terms of image quality, the EF 50mm f / 1.4 USM EF 50mm f / 1.8 II, however, very similar (both lenses are good enough for most applications). Outside the test lab, the EF 50mm f / 1.4 USM but already deliver better pictures alone due to its better autofocus. Who only has a small budget to work with, will be satisfied with the EF 50mm f / 1.8 II. But who can spend a little more, get with the EF 50mm f / 1.4 USM is a lens that is easy to use pleasant.
A much more detailed report I published together with all the test shots, specifications and sample images on my homepage LensTests_de.
