Article by Andrew Matheson in August 1960 PhotoGuide Magazine
THE JUMP IN FILM SPEEDS
Film speeds have a habit of changing when no one is looking. Here are the facts behind the recent (1960) ASA speed changes.
By ANDREW MATHESON, London
OUT of the blue, American film makers have doubled recommended emulsion speeds. What made them do it-and why didn't they do it before?
Speed is one of the most important film characteristics. Measuring it remained the biggest headache in the film industry for nearly half a century. Not because of a lack of methods, but through too many of them. It took nearly fifty years before someone hit on the idea of relating film speed to final print quality. One reason why it took so long was perhaps that it was a cumbersome way, outside and in the laboratory. But it brought order into a chaotic state of affairs. That was the beginning of the ASA (American Standard) exposure index numbers-and later the BS (British Standard) system.
For nearly thirteen years it worked like a charm. Photographers had a figure that they could set on exposure meters and use in exposure tables, and obtain correctly exposed negatives.
Last year the American Standards Association burst into this seemingly peaceful state of affairs. A new standard, made official a few months ago, in effect doubled all previous film speed ratings. At once we are at sixes and sevens again - or more precisely at sixes and dozens. What has happened?
