Canon Inc. and Canon Marketing Japan Inc. announced today the achievement of a new EF lens-manufacturing milestone with the production of the company's 50-millionth lens, an EF100mm f/2.8L Macro IS USM.
Production of interchangeable EF lenses for Canon EOS-series AF (autofocus) single-lens reflex cameras began in 1987 at the company's Utsunomiya Plant, and has since expanded to a total of four production facilities including Canon Inc., Taiwan; Canon Opto (Malaysia) Sdn. Bhd.; and Oita Canon Inc. in Japan. EF lenses reached the 10-million-unit milestone after approximately eight and a half years in production, followed by the 40-million-unit mark in April of 2008. Owing to the popularity of the EOS Digital series, production then increased 10 million units to reach the current 50-million-unit milestone in December 2009 after a mere one year and eight months.
Production of interchangeable EF lenses for Canon EOS-series AF (autofocus) single-lens reflex cameras began in 1987 at the company's Utsunomiya Plant, and has since expanded to a total of four production facilities including Canon Inc., Taiwan; Canon Opto (Malaysia) Sdn. Bhd.; and Oita Canon Inc. in Japan. EF lenses reached the 10-million-unit milestone after approximately eight and a half years in production, followed by the 40-million-unit mark in April of 2008. Owing to the popularity of the EOS Digital series, production then increased 10 million units to reach the current 50-million-unit milestone in December 2009 after a mere one year and eight months.
http://www.canon.com/news/2010/jan29e.html
10 million lenses in 18 months... that's pretty cool 
