Canon EF Extenders

Canon Extender EF 1.4x II

This tele extender can be used with fixed focal length lenses 135mm and longer (except the 135mm f/2.8 Soft focus lens), and the EF 70-200 f/2.8L, 70-200 f/2.8L IS, 70-200 f/4.0L, and 100-400 f/4.5-5.6L IS zoom lenses. Superb optically, it preserves the image quality of the lens it's mounted to and multiplies its focal length 1.4x. Effective aperture is reduced by one f-stop; autofocus is possible on any EOS camera when combined with a lens having an f/4 or faster maximum aperture. The new version II maintains the outstanding optics of the previous version, and adds enhanced weather- resistant construction, and improved anti-reflective surfaces in the barrel.

(When used with EF Extender EF 1.4x II, the EF100-400mm f/4.5-5.6L IS USM lens is compatible for auto exposure with all EOS cameras. However, you lose autofocus with all EOS cameras except those with a 45-point AF system, such as EOS-3, EOS-1v, EOS-1D, EOS-1Ds and EOS-1D Mark II. Only the center focusing point is functional when this lens/extender combination is used with the 45-point AF cameras. Also, when the EF100-400L is used with the EF 1.4x II, the Image Stabilizer function does not work with older EOS 35mm cameras such as the EOS 650, 620, 630/600, RT, 700, 750, 850, EOS-1, A2/A2E, 10s, Elan, Rebel/Rebel S, and Rebel II/Rebel SII.)

Canon Extender EF 2x II

This extender has been re-designed optically and offers excellent performance with compatible EF lenses (same as the Extender EF 1.4x II). Features a new seven-element design, and same weather-resistant design and anti-reflection internal construction as the new EF 1.4x II. The EF 2x II doubles the focal length of any lens it's mounted to, and reduces its effective aperture by two stops. With the EF 2x II, AF is possible with any EOS body if the lens has an f/2.8 or faster maximum aperture, and compatible Image Stabilization lenses maintain the IS feature when used with any current EOS camera.