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MTF-charts for lenses by Canon,
Nikon, Sony, Pentax, Olympus,
Sigma, Tamron, Carl Zeiss, etc.
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0 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.
USM
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:Posted by: Radovan 25.02.2013 12:40:14
USD
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:Posted by: Radovan 24.02.2013 22:32:58
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