The Canon Extender RF 1.4x is the best choice for photographers who wish to have more zoom range with their RF lenses. As the focal range is extended by a factor of 1.4, it's ideal for sports, nature and report photographers. The extender is equipped with high-refraction low-dispersion glass to control curvature of field and chromatic aberration, for the highest image quality.
In addition to optimised lens coatings, a three-layer combined lens helps reduce ghosting by minimising surfaces that come in contact with the air. The exterior is covered with the same white heat shield coating as used on the RF 100-500mm F4.5-7.1L IS USM and RF 70-200mm lenses, to prevent deterioration when performing in high temperatures. A mechanism that limits the zoom of the RF 100-500mm F4.5-7.1L IS USM zoom range (300 to 500mm) prevents the lens elements from hitting those of the extender.
The extender designed for reliability and durability with shock resistance and dust and water resistance, for use by professionals and more experienced amateurs.