Lense with plastic tube

[zzyzx]

Just to survey whose lense whcih comes in plastic tube/thread had crack? i went down to mscolor just now and had a casual chat with the uncle and he told me that if tighten the lense too tight will cause it to crack. fair enough. but how tight is tight? cannot be dun let the thread "bite" what.. wat if the lense drop off while slinging the camera on shoulder?

:dunno:

btw mine is a raynox teleconverter and i inspectedthe thread and found it to have no damage. i applied a little grease on the thread and it makes installing or the lense to my camera a lot easier..