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Tamron 20-40mm f/2.8 Di III VXD — Prime/zoom
Tamron

Tamron 20-40mm f/2.8 Di III VXD

Prime/zoom

85
/ 100
From $699
VS
Canon RF 28-70mm f/2L USM wins by 11
Canon RF 28-70mm f/2L USM — Prime/Zoom
Canon

Canon RF 28-70mm f/2L USM

Prime/Zoom

96
/ 100
From $2,999
Specdex verdict

Canon RF 28-70mm f/2L USM takes it — here’s why.

In our weighted Specdex score, Tamron 20-40mm f/2.8 Di III VXD lands at 85 and Canon RF 28-70mm f/2L USM at 96. That puts Canon RF 28-70mm f/2L USM ahead by 11 points — a decisive margin driven mostly by its strengths in the categories below.

Pick Tamron 20-40mm f/2.8 Di III VXD if…

  • ✓Proven optical formula
  • ✓Weather-sealing (L/GM/S)
  • ✓Strong resale

Pick Canon RF 28-70mm f/2L USM if…

  • ✓Fast autofocus
  • ✓Weather-sealed
  • ✓Premium optics
Tamron 20-40mm f/2.8 Di III VXD 85
vs
96 Canon RF 28-70mm f/2L USM

Score breakdown

Tamron 20-40mm f/2.8 Di III VXD
85
sharpness 85
af 81
build 90
value 86
Canon RF 28-70mm f/2L USM
96
sharpness 96
af 95
build 94
value 84

Specs side-by-side

Tamron 20-40mm f/2.8 Di III VXD versus Canon RF 28-70mm f/2L USM — full spec comparison
Spec Tamron 20-40mm f/2.8 Di III VXD Canon RF 28-70mm f/2L USM

Tamron 20-40mm f/2.8 Di III VXD

Pros
  • +Proven optical formula
  • +Weather-sealing (L/GM/S)
  • +Strong resale
Cons
  • −Mount-specific
  • −Older AF motor on some
  • −Heavier than modern counterparts

Canon RF 28-70mm f/2L USM

Pros
  • +Fast autofocus
  • +Weather-sealed
  • +Premium optics
Cons
  • −Heavy
  • −Expensive
  • −Focus breathing varies

FAQ: Tamron 20-40mm f/2.8 Di III VXD vs Canon RF 28-70mm f/2L USM

Which is better, Tamron 20-40mm f/2.8 Di III VXD or Canon RF 28-70mm f/2L USM? +

Canon RF 28-70mm f/2L USM scores 96 on our weighted rubric — ahead by 11. Your best pick depends on the sub-scores above.

Is Tamron 20-40mm f/2.8 Di III VXD worth the price? +

At $699, Tamron 20-40mm f/2.8 Di III VXD delivers a Specdex score of 85 — strongest in build.

Is Canon RF 28-70mm f/2L USM worth the price? +

At $2,999, Canon RF 28-70mm f/2L USM delivers a Specdex score of 96 — strongest in sharpness.

Does Tamron 20-40mm f/2.8 Di III VXD or Canon RF 28-70mm f/2L USM last longer? +

Based on our long-term update and support ratings, both ship with multi-year support. Battery and reliability scores are visible in the breakdown above.