Hi Dan,I really like my 24-70 f4, but it is also a collapsing lens. It doesn't lock, though, you just have to twist the lens without pushing any unlock button.
Thanks for this info. It sounds the same as the 24-50 with a twist to open, but no locking button.
I might get used to it, but would prefer a lens that doesn't have that feature, even if it makes it a bit longer.
I am wondering if the Z 24-200 has that same feature. If so, then it looks like a Z prime lens is my next purchase.