Description
The Canon EF 2x III Extender doubles the focal length of a compatible telephoto lens at a cost of 2 stops of light — an f/2.8 lens becomes an f/5.6 — while keeping full electronic communication with a compatible EOS body.
Optics
Where earlier extenders cost noticeable sharpness, the Mark III version holds image quality close to the base lens, letting a production extend an existing telephoto rather than buying a larger, more expensive one. Because autofocus performance depends on available light, and most bodies lose AF below f/5.6, we recommend pairing this extender with f/2.8-or-faster lenses — the professional 1-series bodies are a notable exception, autofocusing down to f/8.
Build
Dust- and water-sealed construction and a fast-mounting release mechanism suit demanding conditions, well suited to photojournalism, wildlife, nature and sports work.
Compatible only with fixed focal length L-series lenses 135mm and over, plus the Canon 70-200mm f/2.8L IS III, 300mm f/2.8L IS and EF 100-400mm f/4.5-5.6L — check your lens or camera manual for full compatibility.
