I am looking to expand my lens selection and was looking at the Canon 50mm prime on B&H and saw 2 choices in that length the f/1.4 and the f/1.8, I also noticed a vastly different price between the two. The f/1.8 is about $80 and the f/1.4 is $300. Is the 1.4 that much better of a lens to command the $220 price difference? I can afford the $300, that isn't an issue, I just would like to know if the image quality is that much better out of the 1.4 to make it worth the extra $220 over the 1.8.