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Canon RF 15-35mm f/2.8 L IS USM vs Canon RF 10-20mm f/4 L IS STM

Both are Canon RF mount zooms for wide-angle and landscape — here's how the specs differ and which to pick. Every spec is from the manufacturer's own catalog.

Last verified 2026-06-21 · Canon RF mount · prices change — check the retailer

SpecCanon RF 15-35mm f/2.8 L IS USMCanon RF 10-20mm f/4 L IS STM
Focal length15-35mm10-20mm
Max aperturef/2.8f/4
Typezoomzoom
Coveragefull-framefull-frame
MountCanon RFCanon RF

Which should you buy?

Where to buy

Check the Canon RF 15-35mm f/2.8 L IS USM price on Amazon →

Check the Canon RF 10-20mm f/4 L IS STM price on Amazon →

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FAQ

What's the difference between the Canon RF 15-35mm f/2.8 L IS USM and the Canon RF 10-20mm f/4 L IS STM?
The Canon RF 15-35mm f/2.8 L IS USM is 15-35mm f/2.8 zoom, full-frame; the Canon RF 10-20mm f/4 L IS STM is 10-20mm f/4 zoom, full-frame. Both fit the Canon RF mount.

Which is better in low light, the Canon RF 15-35mm f/2.8 L IS USM or the Canon RF 10-20mm f/4 L IS STM?
The Canon RF 15-35mm f/2.8 L IS USM — its f/2.8 maximum aperture lets in more light and gives more background blur than the f/4 of the other.

Do the Canon RF 15-35mm f/2.8 L IS USM and Canon RF 10-20mm f/4 L IS STM 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).

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