I have a Tamron 28-75 f2.8 lens on my Canon 60d body. I have noticed the great price now for the Canon EF 50mm f/1.8 II prime Lens and like it, but wonder do I need it? I enjoy most aspects of photography including landscape, portraiture and the rest, and obviously like the 50mm f1.4 even more but can't really afford it. The question is, are the low light optics and sharpness of the f1.8 any superior to my Tamron for portraiture especially? I shall be very interested in your views on this!