Specifically, Canon suggests that AF drive speed is reduced by 50% when using the 1.4x Extender, and speed is reduced by 75% when using the 2x Extender. Canon has indicated that autofocus speed Introducing Canon's second generation of IS super-telephoto lenses: EF 300mm f/2.8L IS II USM, EF 400mm f/2.8L IS II USM, EF 500mm f/4L IS II USM and EF 600mm f/4L IS II USM Each Series III Extender features a newly developed microcomputer that increases AF precision when the extenders are used with an IS II super-telephoto lens. The Image Stabilizer function cannot be used with the cameras *2 listed below. EF 1.4x III and EF2x III extenders are recommended for use with EOS Digital Cameras. *1: EOS-1D Mark II, EOS-1Ds Mark II, EOS-1D Mark II N, EOS-1D, EOS-1Ds Newer Mirrorless cameras with DPAF perform quite fast with the EF 100-400mmL II lens and you can use the extenders now with these new model cameras and still have full AF performance, even with the 2x Extender. The EF 1.4x III extender is quite snappy (fast) on any of the DSLRs with DPAF sensors and can be a useful accessory for birders and The long focal length and superior optics makes this lens ideal for avian photography. The original EF 600mm f/4 IS was a very sharp lens and it performed very well with the Canon EF extenders, including the latest EF 1.4X and 2X extender III. Despite great optics and the versatility to cover focal lengths from 600mm to 1200mm, the original EF by Andrew Alexander The Canon 2x lens extender doubles the focal length of a lens, making (for example) a 200mm lens function as a 400mm lens. The 2x series was introduced in 1987, updated Ease of Use. In terms of its size and weight, the Canon EF 70-200mm F2.8L IS III USM is in the middle of the pack for an F2.8 70-200mm lens, measuring 20cms in length and weighing in at 1.48kg. It's about the same size as the Tamron SP 70-200mm F/2.8 Di VC USD G2 and noticeably lighter than the Sigma 70-200mm f/2.8 DG OS HSM Sports lenses. Canon Extender EF 1.4x II. Canon Extender EF 2x II . Sample Images (many more in the review) top. Sample Images Intro Specs Performance. Compared Usage Recommendations More. Flower, December 2014. Canon 5D Mark III, Canon EF 180mm f/3.5 L, f/3.5 (wide open) at 1/500 at ISO 100, no lens profile used, Athentech Perfectly Clear v2.) bigger. .

canon extender ef 2x iii sample images