Canon RF 28-70mm f/2.8 IS STM vs Tamron 17-70mm f/2.8 Di III-A VC RXD

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 28-70mm f/2.8 IS STM	Tamron 17-70mm f/2.8 Di III-A VC RXD
Focal length	28-70mm	17-70mm
Max aperture	f/2.8	f/2.8
Type	zoom	zoom
Coverage	full-frame	APS-C
Mount	Canon RF	Canon RF

Which should you buy?

the Canon RF 28-70mm f/2.8 IS STM covers 28-70mm and the Tamron 17-70mm f/2.8 Di III-A VC RXD covers 17-70mm — pick the range that matches what you shoot
the Canon RF 28-70mm f/2.8 IS STM covers full-frame (also works on APS-C bodies); the Tamron 17-70mm f/2.8 Di III-A VC RXD is APS-C-only — it won't fill a full-frame sensor
the Canon RF 28-70mm f/2.8 IS STM is first-party (Canon) for guaranteed full autofocus and in-camera corrections; the Tamron 17-70mm f/2.8 Di III-A VC RXD is third-party — usually the value pick

Where to buy

Canon RF28-70mm F2.8 is STM Macro Lens, Black

Canon RF 28-70mm f/2.8 IS STMSee price on Amazon

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Tamron 17-70mm F/2.8 Di III-A VC RXD Standard Zoom Lens for Canon RF APS-C Mirrorless Cameras

Tamron 17-70mm f/2.8 Di III-A VC RXDSee price on Amazon

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FAQ

What's the difference between the Canon RF 28-70mm f/2.8 IS STM and the Tamron 17-70mm f/2.8 Di III-A VC RXD?
The Canon RF 28-70mm f/2.8 IS STM is 28-70mm f/2.8 zoom, full-frame; the Tamron 17-70mm f/2.8 Di III-A VC RXD is 17-70mm f/2.8 zoom, APS-C. Both fit the Canon RF mount.

Do the Canon RF 28-70mm f/2.8 IS STM and Tamron 17-70mm f/2.8 Di III-A VC RXD 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 Tamron 17-70mm f/2.8 Di III-A VC RXD 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 28-70mm f/2.8 IS STMAffiliate linkSee price on Amazon