I am doing a little research into the history of Kodachrome and am trying to find out what was the ISO/ASA of the first versions of Kodachrome slide film (35mm and 828 format), i.e., from its release in 1936 until around 1961, when Kodachrome II (ASA 25) took over. In my poking around, I've seen answers for this question ranging from ASA 6 up to 16, with ASA 10 or 12 being the most common ones. What is THE correct answer? Is there more than one correct answer? I've gotten pretty consistent answers for the speed of the early 16mm and 8mm movie films, ASA 10 for daylight and ASA 16 for "Type A", which I assume was some sort of indoor version, but nothing so clear for the slide versions.