These lenses are used between any compatible EF type lens, and any of the Canon EOS line of cameras.
When used with a compatible lens, such as the Canon EF 500mm f/4L IS USM they will multiply the focal length of the lens by a factor of either 1.4× or 2.0×. This will result in a focal length of 700mm or 1000mm, respectively.
Four Extender EF lenses have been available.
These Extender EF lenses can only be used with lenses that have a compatible mount. While all EF lenses have mount designs that can be used with EOS bodies, only lenses with accordant mounts can be used with the extender EF lenses. These lenses must have the clearance to accept the protruding lens on the extender, as well as 10(3 extra) electronic contacts for proper electronic communication with the extender. These extra electronic contacts are used for sending the correct aperture information to the body. When a compatible lens is used with an 1.4× or 2× extender, it will cost the lens a one stop, or two stop decline in aperture size, respectively. Autofocus speed of any used EF lens is also affected. When used with the 1.4× extender, autofocus speed is reduced to a half. When used with the 2× extender, autofocus speed is reduced to a quarter. Image stabilization may not work on lenses that are equipped with one, when used with an extender, and certain EOS bodies.
Though not specified by Canon as such, users have reported that the tilt-shift lenses in Canon's line-up can also be used with the extenders. However, when used with an extender, the lens will not pass on the correct aperture to the camera. The focal length stored in the EXIF data will also be incorrect.
|Lens||Lens with 1.4×||AF with 1.4×||IS with 1.4×||Lens with 2×||AF with 2×||IS with 2x|
|135 mm 2L USM||190 mm 2.8||—||270 mm 4||—|
|180 mm 3.5L Macro USM||252 mm 5||†||—||360 mm 7.1||—|
|200 mm 1.8L USM||280 mm 2.5||—||400 mm 3.5||—|
|200 mm 2.0L IS USM||280 mm 2.8||400 mm 4|
|200 mm 2.8L II USM||280 mm 4||—||400 mm 5.6||—|
|300 mm 2.8L USM||420 mm 4||—||600 mm 5.6||—|
|300 mm 2.8L IS USM||420 mm 4||600 mm 5.6|
|300 mm 4L USM||420 mm 5.6||—||600 mm 8||—|
|300 mm 4L IS USM||420 mm 5.6||600 mm 8|
|400 mm 2.8L USM||560 mm 4||—||800 mm 5.6||—|
|400 mm 2.8L II USM||560 mm 4||—||800 mm 5.6||—|
|400 mm 2.8 IS USM||560 mm 4||800 mm 5.6|
|400 mm 4L IS DO USM||560 mm 5.6||800 mm 8|
|400 mm 5.6L USM||560 mm 8||—||800 mm 11||—|
|500 mm 4L IS USM||700 mm 5.6||1000 mm 8|
|500 mm 4.5L USM||700 mm 6.3||—||1000 mm 9.0||—|
|600 mm 4L USM||840 mm 5.6||—||1200 mm 8||—|
|600 mm 4L IS USM||840 mm 5.6||1200 mm 8|
|800 mm 5.6L IS USM||1120 mm 8||1600 mm 11|
|1200 mm 5.6L USM||1680 mm 8||—||2400 mm 11||—|
|70-200 mm 2.8L IS USM||98-280 mm 4||140-400 mm 5.6|
|70-200 mm 2.8L USM||98-280 mm 4||‡||—||140-400 mm 5.6||‡||—|
|70-200 mm 4L IS USM||98-280 mm 5.6||140-400 mm 8|
|70-200 mm 4L USM||98-280 mm 5.6||—||140-400 mm 8||—|
|100-400 mm 4.5-5.6L IS USM||140-560 mm 6.3-8||200-800 mm 9-11|
|TS-E 24mm 3.5L||35 mm 5.0||¥||—||50mm 7.1||¥||—|
|TS-E 45mm 2.8||65 mm 4.0||¥||—||90mm 5.6||¥||—|
|TS-E 90mm 2.8||125 mm 4.0||¥||—||180mm 5.6||¥||—|
|Autofocus:||- AF works. - AF works only with EOS bodies that can AF at 8. - AF does not work.|
|Image stabilization:||- IS works. - IS works only with supported EOS bodies.|
† - When the Canon 180 mm 3.5L Macro USM is used with the Extender EF 1.4×, AF will only work from 0.8m - infinity, you must focus manually from 0.48m - 0.8m.
‡ - Will only autofocus with center AF point.
¥ - TS-E lens, isn't equipped with an autofocus motor.