White paper

10.1.3! !!!!!!!!Focus&Ring&Rotation&Direction&Change!
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The!RF!lens e s!all!incorpora te !an!ability!to !choose!th e !direction!of!rotation!of!the!man ua l!focus!cont ro l.!!!
In! p la ce !of! a!direct!mechanical!co n n ec tio n !from!focus!control!ring!to!th e!actual!focusin g!optics,!throug h !
a! threaded,! all! mechanical! helicoid,!the! system! uses! a! focus!ring! co nn ec ted ! to! a! se ries! of! ma ny ! very!
fine,! electronic ! c on tacts .! ! There's! no! d irec t,! m e ch an ical! connection! a t! a ll! to ! th e! group(s)! of! elements!
that!move!the!focusing!element.!!Ro tating !the!focus!ring!se nd s!a!series!of!very!specific,!fine!signals!to!
these!contacts.!!These!are!converted! into! signals!to!the!sam e!focus!motor!(USM,!Nano!USM,!etc.)! that's!
used!for!autofocus.!!The!motor!now!drives!the!lens!to!change!focus.!
Inheren t !to !t h is!s ys te m!there!is!a!cus to m!function!t o !ch a n g e!Manual!Fo cu s !d ire ct io n,!wh ich !c an !b e !an !
invaluab le !as se t !to !u se rs !tra n sit ion in g !to !C a n on !fr o m !c o m p e tit ive !sy s te m s . !!!Th is!also!benefit!users!who!
utilize!a!follow!focus!system!(external!gears!and!a!knob!to!control!focus)!.!
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10.1.4&&&&&&&Enhanced&Electronic&Communication&between&Lens&and&Camera&
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The! new! RF! mount! uses! 12! contacts! instead! of! the! 8! contacts! of! the! EF! lenses! fo r! lens-cam era!
communication.! ! New ! communication! protocols! and! dedicated! communication! ch annels! are!
incorpo ra te d!—!which!support!large!data!transfers! a t!very!high!speeds!compared!to!current! EF!system.!!
The!new! RF!system!design!anticipates!ongoing!innovations!in!future!cameras!as!well!as!lenses.!!Even!
with!these!changes,!full!support!and!compatibility!for!existing!Canon!EF!and!EF-S!lenses!remain.!
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11.0&&& INTRODUCTORY&FAMILY&OF&CANON&RF&LENSES&&
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This!white!paper!will!outline!four!lenses!that!constitute!the!introductory!phase!of!the!new!RF!system:!
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10.1! ! RF28-70mm!F2!L!USM!
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10.2! ! RF50mm!F1.2!L!USM!
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10.3! ! RF24-105mm!F4!L!IS!USM!
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10.4!!!!!!!! RF35mm!F1.8!MACRO!IS!STM!!
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