While I am at it. Photo history also includes how to asess light conditions. Here is a copy of a post i placed at "collection-appareils.fr".
J` ai trouve le livre systematique "Deutsche Belichtungsmesser" par H.Thiele . Let me continue in English: the book is well illustrated and lists the history of all German lightmeters. It was published by the author and is probably available from any good photobookstore (to avoid advertizing; myself i use the specialized photobookstore with a name that starts on L in Stuttgart they deliver expensively but fast even here in Norway)
p.
