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Glossary of Terms (2)

A regularly updated collection of terms, definitions, abbreviations and acronyms related to photographic lenses. You must be logged in to add a term.

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USM stands for Canon's Ultrasonic Motor it's an AF (auto focus) driving motor. Usually contained in lens name eg. (EF-S 15-85 mm f/ 3.5-5.6 IS USM) and in gold lettering on lens barel (ULTRASONIC). All detail about Ultrasonic Motor technology can be found here. Other after-market lens manufacturer call their ultrasonic motors by different name for Sigma it is called HSM and Tamron calls it USD

Source: Canon museum USM
Posted by: Radovan 25.02.2013 12:40:14


USD stands for Tamron's proprietary Ultrasonic Silent Drive used in their lenses to achieve silent and high-speed AF. Usually contained in lens name eg. (SP 70-200mm F/2.8 Di VC USD) Translated to Canon terminology it equals to USM (Ultrasonic Motor) or for Sigma it's HSM (Hyper-Sonic Motor)

Source: Tamron Technical Glossary
Posted by: Radovan 24.02.2013 22:32:58

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