Canon tele extenders are available in 1.4x and 2.0x magnification factors.
Canon tele extenders include an integrated microprocessor/microcomputer that maintains camera–lens communication so autofocus, exposure metering, and image stabilization data are passed through and preserved.
Canon tele extenders are commonly used for sports, wildlife, nature, and event photography when additional reach is needed.
Canon tele extenders use a lens mount design that enables quick attachment and helps limit exposure to the elements during mounting. Front and rear optical elements are treated with a fluorine coating to resist water, dust, fingerprints and smudges.
Tele extenders increase reach (for example 1.4x and 2x) while reducing the amount of light reaching the sensor — the 1.4x extender is noted to cause about a 1-stop light loss. Canon’s optical designs and coatings are used to reduce ghosting and flare and help preserve clarity and contrast, and an integrated microcomputer maintains autofocus and exposure metering communication.
Typical package contents shown include the extender plus front and rear caps, a lens case, a manual, and warranty information. Product details also list a 1 Year Limited Warranty in some listings; not every listing explicitly shows all included accessories.