According to trust source from CR. The long rumored EF 100-400mm f/4.5-5.6L IS II USM lens will be finally hit on the market in November 2014. A demo version of this lens is already send to select photographers hands for field use.
The new design resembles the EF 70-300 f/4-5.6L IS with a thin focus ring at the base, and a wider zoom ring near the front element. The aperture range for the lens will remain at f/4.5-5.6. Another mentioned feature is in the lens hood for the lens. It sounds like there will be a retractable opening near where a filter would be, so you could turn your circular polarize easily if you needed to.
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