So I just purchased this lens new on Amazon and wasn't sure if this is how all the lens behaved or is it just mine? Need to know if I need to exchange or not. When you zoom all the way out to 12mm, the barrel doesn't sit all the way back, but extends a tad bit. When you start to zoom in to 16mm, the barrel is pulled all the way back where I expect 12mm to have been. As you zoom in more, towards 40mm, it extends as expected. Does that make sense or should I need to make a video? I also have a Canon 24-70mm L lens that I just simulated to see if it had the same behavior and it didn't. Can anybody with the same lens confirm this? Thanks in advance.