My older No. 1A autographic Jr. uses the "US" scale for aperture... ( "Universal System" ). Easy enough to convert, but you get to set it to a whopping 128 for F45... Then my Weston meter used "Weston emulsion speeds" instead of asa or iso. When I got my newer autographic, I had to convert F-system back to US system to understand what I was doing... round and round and round... All of which is a lot more satisfying than pointing a telephone at the scene...