Good day my fellow photo enthusiasts. I am going to buy one of two lenses this week. I have narrowed my selection down to the Canon 70-200 f4L vs Sigma 50mm f1.4 and I'm not sure what to do? First thing that pops into my head is that i often like to take shots with a shallow DOF and I enjoy using my Canon 50mm f1.8 often. I take shots at events sometimes and like to shoot around f2.8 and the sigma is well known for its quality at this aperture and i feel that if i sell my lens this one will only cost me $450ish after using my time to sell the other lens and i feel this is the lens i truly want. Then in the back of my head i see the canon 70-200 is on sale and i would save around $50 and going for the good deal is usually my first instinct. I am slightly bothered about the sigma having reviews about front or back focus badly and sigma needing me/you to send our cameras in to calibrate the lens? This sounds like a good idea to me other then knowing some person will be fondling my camera thoroughly. What do you think and why does my photographer friend keep telling me to shoot wide?