FitMyLensthe lens-by-mount reference

Canon RF 50mm f/1.8 STM vs Canon RF 135mm f/1.8 L IS USM

Both are Canon RF mount primes for low-light — 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 50mm f/1.8 STMCanon RF 135mm f/1.8 L IS USM
Focal length50mm135mm
Max aperturef/1.8f/1.8
Typeprimeprime
Coveragefull-framefull-frame
MountCanon RFCanon RF

Which should you buy?

Where to buy

Check the Canon RF 50mm f/1.8 STM price on Amazon →

Check the Canon RF 135mm f/1.8 L IS USM price on Amazon →

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FAQ

What's the difference between the Canon RF 50mm f/1.8 STM and the Canon RF 135mm f/1.8 L IS USM?
The Canon RF 50mm f/1.8 STM is 50mm f/1.8 prime, full-frame; the Canon RF 135mm f/1.8 L IS USM is 135mm f/1.8 prime, full-frame. Both fit the Canon RF mount.

Do the Canon RF 50mm f/1.8 STM and Canon RF 135mm f/1.8 L IS USM 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).

More Canon RF comparisons: Canon RF 50mm f/1.2 L USM vs Canon RF 50mm f/1.4 L VCM · Canon RF 100-400mm f/5.6-8 IS USM vs Canon RF-S 55-210mm f/5-7.1 IS STM · Canon RF 50mm f/1.2 L USM vs Canon RF 85mm f/1.2 L USM · Canon RF 50mm f/1.2 L USM vs Canon RF 135mm f/1.8 L IS USM · all Canon RF lenses · all comparisons