Prior to the introduction of the Canon EF 50mm f/1.2 L USM Lens, the Canon 50mm standard lens choices were the Canon EF 50mm f/1.8 II Lens (below left), Canon EF 50mm f/1.4 USM Lens (below center) and Canon EF 50mm f/2.5 Macro Lens. The f/1.8 lens is an excellent value (sharp images for a cheap price) but offers little in terms of build quality. AF is slow and loud. The f/1.4 lens is a step up in build quality but is still in the middle of Canon's build quality range. The f/1.4 offers excellent image quality if stopped down to at least f/2 or f/2.8. AF is quieter and faster than the f/1.8 but not as fast as Canon's best lenses - and is poorly damped. The f/2.5 macro is only half-a-macro (.5x), has mediocre build quality and has a rather slow aperture for a prime lens in this focal length range. It has slow, loud AF. A long-discontinued Canon EF 50mm f/1.0 L Lens is available for an extremely high price on the used market, but the Canon EF 50mm f/1.4 USM Lens was the best 50mm lens available new prior to the 50 f/1.2's release. There was definitely an opening in Canon's lens lineup for a new high quality, professional grade 50mm lens. Read the full review here