Canon RF 24-70mm f/2.8 L IS USM vs Sigma 17-40mm f/1.8 DC Art

Both are Canon RF mount zooms for pro standard zoom and everyday — here's how the specs differ and which to pick. Every spec is from the manufacturer's own catalog.

Last verified 2026-09-01 · Canon RF mount · prices change — check the retailer

Spec	Canon RF 24-70mm f/2.8 L IS USM	Sigma 17-40mm f/1.8 DC Art
Focal length	24-70mm	17-40mm
Max aperture	f/2.8	f/1.8
Type	zoom	zoom
Coverage	full-frame	APS-C
Mount	Canon RF	Canon RF

Which should you buy?

the Sigma 17-40mm f/1.8 DC Art opens wider (f/1.8) — brighter in low light and more background blur
the Canon RF 24-70mm f/2.8 L IS USM covers 24-70mm and the Sigma 17-40mm f/1.8 DC Art covers 17-40mm — pick the range that matches what you shoot
the Canon RF 24-70mm f/2.8 L IS USM covers full-frame (also works on APS-C bodies); the Sigma 17-40mm f/1.8 DC Art is APS-C-only — it won't fill a full-frame sensor
the Canon RF 24-70mm f/2.8 L IS USM is first-party (Canon) for guaranteed full autofocus and in-camera corrections; the Sigma 17-40mm f/1.8 DC Art is third-party — usually the value pick

Where to buy

Canon RF24-70mm F2.8 L is USM Lens, Mirrorless Lens, Standard Zoom, Compatible with EOS R Series Mirrorless Cameras, Hig

Canon RF 24-70mm f/2.8 L IS USMSee price on Amazon

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Sigma 17-40mm F1.8 DC | Art for Canon RF, Black

Sigma 17-40mm f/1.8 DC ArtSee price on Amazon

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FAQ

What's the difference between the Canon RF 24-70mm f/2.8 L IS USM and the Sigma 17-40mm f/1.8 DC Art?
The Canon RF 24-70mm f/2.8 L IS USM is 24-70mm f/2.8 zoom, full-frame; the Sigma 17-40mm f/1.8 DC Art is 17-40mm f/1.8 zoom, APS-C. Both fit the Canon RF mount.

Which is better in low light, the Canon RF 24-70mm f/2.8 L IS USM or the Sigma 17-40mm f/1.8 DC Art?
The Sigma 17-40mm f/1.8 DC Art — its f/1.8 maximum aperture lets in more light and gives more background blur than the f/2.8 of the other.

Do the Canon RF 24-70mm f/2.8 L IS USM and Sigma 17-40mm f/1.8 DC Art fit the same camera?
Yes — both are Canon RF mount lenses, so they fit Canon EOS R series (full-frame R5/R6/R8) and APS-C (R7/R10/R50). Note the Sigma 17-40mm f/1.8 DC Art is APS-C-only and won't fill a full-frame sensor.

Citing these specs? Go ahead — manufacturer data, last verified 2026-09-01. Copy a ready-made reference:

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Canon RF 24-70mm f/2.8 L IS USMAffiliate linkSee price on Amazon