Used Canon EF Extender 2x II

Condition & contents

At a glance: EF 2x II teleconverter - doubles compatible L-series telephotos, 2-stop aperture loss.

About this lens

The Canon EF Extender 2x II is Canon's earlier 2x teleconverter, doubling the focal length of compatible L-series telephotos at a cost of two stops of aperture. Used extensively with the 300mm, 400mm, 500mm and 600mm L-series primes to extend reach without adding another lens to the kit.

Build & handling

Works with

• Canon L-series telephoto lenses only (see Canon compatibility chart)
• Works on Canon EF-mount full-frame and APS-C DSLRs
• AF performance varies - best on 5D III/IV/5Ds, 7D II, 1D X series, which AF at f/8

Best for

A 2x teleconverter for extending the reach of compatible Canon L-series telephoto lenses. Stacked on a 300mm f/2.8L it becomes a 600mm f/5.6; on a 400mm f/2.8L it becomes 800mm f/5.6. The two-stop aperture loss means AF may be limited to higher-end Canon bodies, particularly in lower light.

Frequently asked questions

Which lenses is this compatible with?

Only specific Canon L-series telephoto lenses - primarily the 70-200mm f/2.8L IS, 300mm f/2.8L IS, 400mm f/2.8L IS, 500mm f/4L IS, 600mm f/4L IS, and 800mm f/5.6L IS families.

Will autofocus still work with this converter?

Depends on the body and lens combination. With a 2x converter, any f/4 lens effectively becomes f/8. Current Canon bodies (5D III and later, 7D II, 1D X series) support AF at f/8 in the centre AF point. Older bodies may only offer manual focus.

Will it work on Canon RF mirrorless bodies?

Yes, via the Canon EF-EOS R adapter. Autofocus and IS are preserved, and the lens functions normally on R, R5, R6, R7, R8, R50 and other RF bodies.