The Norwegain website Akamera.no have published a test of 3 Canon 50mm lenses - the Canon EF 50mm 1.8 Mark II, Canon EF 50mm 1.4 USM and Canon EF 50mm 2.5 Compact Macro. There are an excellent set of comparitive sample shots so that you can see the differences between the lenses, even if norwegian isn’t one of your strong points.

Website: Akamera.no - Canon 50mm Lenses Test