Does the Canon RF 100-400mm f/5.6-8 IS USM work with a teleconverter?

Canon RF Extender 2x: partially (AF at all zoom settings but AF-area coverage narrows to approx. 40% x 60%.) — giving 200-800mm at f/11-16. Canon RF Extender 1.4x: yes (Canon states a 140-560mm range with the Extender RF1.4x — the full zoom range, no restriction. Aperture is computed, not a Canon figure.) — giving 140-560mm at f/8-11.

How much reach does a teleconverter add to the Canon RF 100-400mm f/5.6-8 IS USM?

A 2x takes it from 100-400mm to 200-800mm, costing 2 stops of light (f/5.6-8 becomes f/11-16). A 1.4x takes it from 100-400mm to 140-560mm, costing 1 stop of light (f/5.6-8 becomes f/8-11).

Does the Canon RF 100-400mm f/5.6-8 IS USM take a teleconverter?

Canon RF · 100-400mm f/5.6-8 · thread and mount data verified 2026-09-02

2 teleconverters are supported. A teleconverter multiplies the focal length and costs you light — and on a crop body the framing multiplies again.

Read the restriction before you buy: AF at all zoom settings but AF-area coverage narrows to approx. 40% x 60%. That is a published limit, not a reviewer's opinion — the usable range with a converter fitted is narrower than the lens's own.

Canon RF Extender 2xSee price on Amazon

Canon RF Extender 1.4x

See price on Amazon

As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Affiliate links never affect our specs or which lenses we compare.

Teleconverter	Supported	Reach	Max aperture	On APS-C	On Micro Four Thirds
Canon RF Extender 1.4x	Yes — Canon states a 140-560mm range with the Extender RF1.4x — the full zoom range, no restriction. Aperture is computed, not a Canon figure.	140-560mm	f/8-11	224-896mm	—
Canon RF Extender 2x	Partial — AF at all zoom settings but AF-area coverage narrows to approx. 40% x 60%.	200-800mm	f/11-16	320-1280mm	—

At f/11-16 autofocus is limited on many bodies (often centre-point only). Check your body's AF aperture limit. At f/8-11 some older bodies restrict autofocus to the centre point.

What each converter gives you

Canon RF Extender 2x — 200-800mm at f/11-16 on this lens, autofocus retained.

Canon RF Extender 1.4x — 140-560mm at f/8-11 on this lens.

The lens itself: Canon RF 100-400mm f/5.6-8 IS USM · every Canon RF lens: Canon RF lens index · all teleconverter compatibility

Compatibility sourced from the manufacturers' own published teleconverter compatibility statements (manufacturer teleconverter compatibility statements (Sony, Canon USA, Nikon, Fujifilm, Sigma, Panasonic, OM System) — each row carries its own source URL) and verified 2026-09-02. Reach and aperture figures are computed from the lens's own published focal length and maximum aperture — a 1.4x multiplies focal length by 1.4 and costs 1 stop; a 2x multiplies by 2 and costs 2 stops. Lenses whose compatibility we could not verify from a manufacturer statement are omitted rather than guessed. Methodology