Review by Klaus Schroiff, published May 2015IntroductionHonestly I can"t remember how many 50mm lenses I reviewed during the last few years but there were many. Seems as if all the manufacturers are or have been in an update frenzy. All of then ? Well, Canon has been a little late in this game. This was especially true for the Canon EF 50mm f/1.8 II which was released back in 1990 ... 25 years ago! Think of that. :-) It almost feels as if they didn"t really want khổng lồ update it but were forced to vị so by Yongnuo, a chinese manufacturer who just started shipping clones of the EF 50mm f/1.8 II (and the old EF 35mm f/2). So finally there"s a new version ... Sort of - the Canon EF 50mm f/1.8 STM. It isn"t really a major update - at least optically. The new lens received a better lens coating and a marginally improved design here.
However, Canon has substantially redesigned the lens body. Unlike its predecessor, it has a metal mount & a decent, rubberized focus ring. The lens barrel is made of plastic with a nice matte finish. Th EF 50mm f/1.8 STM continues khổng lồ use a linear focus extension system so the inner lens tube extends towards shorter focus distances. A barrel-shaped lens hood remains available as an option only.
The lens uses an STM (stepping motor) for auto-focusing. The STM has been optimized khổng lồ deliver "smooth servo AF for movies and a speedy AF for stills". That"s the theory according to Canon at least. Honestly the AF feels as fast as on lớn the EF 50mm f/1.8 II - at best. However, it is certainly more quiet although not as silent as Canon"s USM AF. Anyway, it"s certainly not bad in any case. Typical for all STM-driven lenses, manual focusing works "by-wire" thus you trigger the AF motor by turning the focus ring. This works nicely.
