As a 1.4x teleconverter, the focal length of the attached lens is magnified by a factor of 1.4x, with a 1 f/stop reduction in aperture rating, so a 70-200mm f/2.8 zoom effectively becomes roughly a ...

Just like with any 2x teleconverter, the focal length of the attached lens is doubled, with a consequent aperture reduction of two f/stops. As such, a 70-200mm f/2.8 zoom effectively becomes roughly a ...

Canon's EF 200-400mm f/4L IS USM Extender 1.4x ($10,999) is a behemoth of a lens that ships in a hard carrying case. It's not a good choice for the weak of back, but its optical performance is superb, ...

We spend a day shooting aeroplanes with Andy Rouse to test the new Canon EF 200-400mm f/4L IS USM Extender 1.4x lens. The Canon EF 200-400mm f/4L IS USM Extender 1.4x is a professional quality ...

This month will see the release of Canon’s EF 200-400mm f/4L IS USM Extender 1.4x lens, the first super-telephoto zoom lens to incorporate an internal extender. Side view of the new Canon’s EF ...