 
 <prompt> "Which one get higher model number: Master III or Direct Reading? Based on di last question, write small tori wey contain di answer. E fit be 1 - 20 sentences. Context:" <response>: The Weston Cadet (model 852 wey dem introduce for 1949), Direct Reading (model 853 wey dem introduce for 1954) and Master III (models 737 and S141.3 wey dem introduce for 1956) na di first for their line of exposure meters wey switch and begin use the ASA scale wey don already dey popular. Other models dey use the original Weston scale until around 1955. The company still dey publish Weston film ratings after 1955, but their recommended values sometimes dey different small small from the ASA film speeds wey dey for film boxes, but these new Weston values dey based on the ASA system and you fit convert am for use with older Weston meters by subtracting 1/3 exposure stop as Weston recommend. Vice versa, "old" Weston film speed ratings fit be converted to "new" Westons and the ASA scale by adding the same amount, that is, a film rating of 100 Weston (up to 1955) dey correspond with 125 ASA (as per ASA PH2.5-1954 and before). This conversion no dey necessary for Weston meters wey dem manufacture and Weston film ratings wey dem publish since 1956 because dem dey already use the ASA system; but the changes wey dey for the ASA PH2.5-1960 revision fit dey taken into account when you dey compare with newer ASA or ISO values. 