ISO rating

British

noun

photog a classification of film speed in which a doubling of the ISO number represents a doubling in sensitivity; for example, ISO 400 film requires half the exposure of ISO 200 under the same conditions. The system uses identical numbers to the obsolete ASA rating

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of ISO rating

C20: from I nternational S tandards O rganization

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

As fire protection increases, the ISO rating number decreases, and premiums follow suit.

From Time Magazine Archive

In technical terms, Kodak's new film carries an ISO rating of 1,000, which means that it is 2� times as sensitive to light as any other color print film now on the market.

From Time Magazine Archive

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