Loose focus on a 50 f.18

[whiteflyer]

When using manual focus on my Canon EF 50 f1.8 II , the focus ring seems almost too loose and can move on its own, which throws the focus off. I had my camera mounted on a tripod and pointing down at the subject, and saw the focus ring move just because of the position. Gravity changed the focus!

Is there anyway to tighten this up or do I have to move up to the 1.4

[CT]

I think you're stuck with it. MF on some cheaper lenses is almost an afterthought and they're usually pretty slack. The focus ring on the 1.4 is much as you'd expect it be... smooth and firm.