T3i (600D) front focuses, but not in live view

Hi!

I've had my T3i (600D) for about three weeks now and never noticed any focusing problems with the two kit lenses I have (18-55 and 55-250). I'm a DSLR newbie, mind you. Yesterday I bought a 50 mm 1.8 and tried it out briefly last night. I didn't get the amazingly sharp results everyone seems to be getting with this lens so I continued this morning. Well, after taking some shots of a ruler it seems it is front focusing. I used the center focus point only, and aimed for the 10 mm mark. See below.

The center focus point was aiming at 10 mm.

However, when I used Live View, it managed to get the focus correctly. I assume this has to do with the different focusing systems.



Aiming at 10 mm, shot with Live View.

I also tried the same my kit lenses and it was hard to determine if the focus was off, since they had a deeper DOF. I will probably have to do more testing.

So, given what you have seen so far, is it more probable the lens is faulty or my camera body?

Thanks for any comments on this, so I know if I should contact Canon or the store where I bought the lens.