click for bigger image Click for bigger image When the zoom lens is fitted with the Extender EF 1.4x or EF 2x for use with any EOS cameras having multi-point AF sensors like the EOS 500N, EOS 888, EOS 10, EOS 50/50E, EOS 5 and the EOS 1N / EOS 1N RS cameras, Canon recommended to use only the centre AF point for best results. This is because the AF operations for all the Canon EF lenses that are designed to accept the EF Extenders, the AF speeds are slower in reactions when used with any of the two Extenders. The centre AF point of all the multi-point EOS cameras remains as the core of the EOS autofocus operations, hence it is better equipped to handle the changes in the lens' focal length and AF speed responses. << Back to Main . 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 .