Thanks to all for commenting !
@ Bjørn : my sensor really needs a cleaning. I will try to do it by myself. As for handling, this lens is now permanently in my bag...
@ Akira : the Cornwal history is very interesting. mining (copper and tin), china clay extraction (kaolin), even prehistory. What I really like, is the purity of air and near zero pollution (almost only pastures and grazing)
@ Frank and John : I am glad you like them !