γνωστό πρόβλημα του συγκεκριμένου φακού , δες
εδώ, συνήθως το έχει η ΙΙ βερσιον που έχει στεγανοποίηση , πιθανόν να υπάρχει εκεί στο ζουμ κάποια τσιμουχα που δυσκολευει την κίνηση ή δεν έχει κάτσει καλά
βεβαια οι περισσότεροι LUMIX φακοί που είναι WR έχουν μόνο τσιμουχα στο κούμπωμα οπότε μπορεί να μην είναι αυτη η αιτία
JUST ONE ISSUE
The only gripe I have is in relation to hands-on use. When turning the zoom ring, there’s a noticeable increase of friction at around 1/3rd to 1/2 of full lens extension. If turned slowly in this range, we get a bizarre step-zoom kind of effect that smoothes out completely both before and after the sticky spot. Whilst this causes me no real problem when shooting still images, the apparent stiffness in operation would undoubtedly prevent smooth transition from wide angle to telephoto (and vice versa) when shooting video. Consequently, had I bought the lens specifically for movie making purposes, I’d have been disgruntled by this problem to say the least.
From what I gather, this stiffness is a widely recognised issue that tends to free up the more that the lens is used. I can see how and why this may prove to be true. But I’m puzzled as to how long one has to use the lens before everything frees up.