question: What did the 1960 changes to film speed measures lead to ?
answer: effectively doubling the nominal speed of many black-and-white negative films
turker_answer: The 1960 changes to film speed measures led to effectively doubling the nominal speed of many black-and-white negative films .
rule-based: The 1960 changes to film speed measures led to effectively doubling the nominal speed of many black-and-white negative films .