Build quality of the 50 f/1.8 is very cheap (as you might expect). This lens feels more like a toy than a piece of optics. It utilizes plastic contruction right down to the lens mount (the lenses are glass of course). This light material combined with the small size (2.7" x 1.6"/68.2mm x 41.0mm - WxL) puts this lens in the featherweight class - 4.6 oz (130g). The 50 f/1.8 is currently Canon's lightest. It was also Canon's shortest EOS-mount lens until the Canon EF 40mm f/2.8 STM Lens was introduced.

The 50 f/1./8 bears a plastic lens mount. Considering how light the 50 f/1.8 II lens is, the plastic lens mount seems adequate from a strength perspective. You might get more wear than you wish if you are changing the lens frequently.

There is not much to this lens. There is no distance window or markings. There is barely even a focus ring - and the tiny ring that is there is barely usable.

Autofocus is driven by a micro motor. Focus speed is not stellar, but fine in good light with subjects that are not moving too quickly. The 50 f/1.8 II is one of Canon's louder/buzzier lenses - you know when it is focusing. But this is not a wildlife lens - and the noise probably won't bother most people. I suppose a positive aspect of the sound is that you know when it is working - and when it is finished working - when focus is locked. FTM (Full Time Manual) focusing is not included. The 50 f/1.8 extends up to 5/16" during focusing - the very small 52mm filter does not rotate.