According to CR, a new super telephoto zoom EF 200-600mm f/4.5-5.6 IS USM lens is currently in development. It will be announced later this year.
The EF 200-600mm f/4.5-5.6 IS USM lens will probably be a non-L lens. It will be priced below current EF 100-400mm f/4.5-5.6L IS II USM lens. This lens is compete directly with the Sigma and Tamron supertelephoto zoom lenses (150-600mm).
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