I recently bought a used Canon 24-70mm F2.8L lens used off of Craigslist. (The seller wasn't sketchy at all btw). It's in perfect conditionally visually, and after testing it I didn't notice anything off, but after using it a bit more, I've noticed that at F2.8, bright edges seem to spill out. I've used a 24-70 a lot before, but I've never actually owned one. I'm pretty sure this is not normal. In the attached pictures, the first one is my 24-70 at 70mm F2.8. The second one is at 70mm F4.0. You can see the all of the lights have a bokeh effect. The focus point is on the left traffic light. If I could attach a third file I'd attach a comparison of my 70-200mm at F4, but I'll just say that it is much much sharper. I've put it on a tripod and used live view 10x magnification on my 60D to see if it was an AF issue but no matter how I adjust the focus this is the best it gets. Does anybody know what this problem (if it actually is a problem) and if it is, should I be chasing this guy for my money back? Thanks in advance.