When I first got my Yongnuo 50mm f/1.8 it would not focus through the viewfinder. It will always miss (95% of times). Yet it worked fine in liveview. And now, recently, I started noticing the same issue with my 18-55mm. I reviewed some pictures a friend took 2 weeks back (using my body) and the AF is always a little off. It's never really there!
I tested this with multiple focus points today, I placed two toy figures a few inches apart in the middle of the room against a white wall and took a bunch of test shots. It either grossly missed focused or came really close at smaller apertures. At best, toy figures had a soft look, whereas the same shots come out crisp when taken in liveview!
P.S my kit lens worked fine on a friend's 70D (I haven't tried it recently though)
Body: Canon SL1
Lenses: 18-55mm Kit; Youngnou 50mm f1.8
Summary: Camera won't focus through viewfinder; works fine when operated through liveview.
What can possibly be the cause, and how can I fix this?