In working with the Z1 in subzero weather (sub zero FARENHEIT), you may have noticed that the lens shade on the Z1 or FX1 sticks when it gets too cold.
This is further exacerbated by dust/dirt in the hood from extended outdoor use. Mine's been in constant use for several months now, and when the lens hood got cold, I forced it. Bad move.
Anyway, here is a short tutorial on fixing this problem if you do what I did.
http://www.sundancemediagroup.com/articles/repairing_the_Sony_Z1_lens_hood.htm