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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
Tamron 20-40mm f/2.8 Di III VXD wins by 1
Viltrox AF 13mm f/1.4 STM — Prime/zoom
Viltrox

Viltrox AF 13mm f/1.4 STM

Prime/zoom

84
/ 100
From $449
Specdex verdict

Tamron 20-40mm f/2.8 Di III VXD takes it — here’s why.

In our weighted Specdex score, Tamron 20-40mm f/2.8 Di III VXD lands at 85 and Viltrox AF 13mm f/1.4 STM at 84. That puts Tamron 20-40mm f/2.8 Di III VXD ahead by 1 points — a narrow 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 Viltrox AF 13mm f/1.4 STM if…

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

Derived from the sub-score breakdown · not a separate test

Build

Tie

Compared on the build sub-score

Effectively tied — neither pulls a 2-point weighted lead.

Sharpness

Tie

Compared on the sharpness sub-score

Effectively tied — neither pulls a 2-point weighted lead.

Autofocus

Tie

Compared on the autofocus sub-score

Effectively tied — neither pulls a 2-point weighted lead.

Value for money

Viltrox AF 13mm f/1.4 STM

Specdex score per dollar at MSRP

Viltrox AF 13mm f/1.4 STM more score per dollar ($449 vs $699).

Tamron 20-40mm f/2.8 Di III VXD 85
vs
84 Viltrox AF 13mm f/1.4 STM

Score breakdown

Tamron 20-40mm f/2.8 Di III VXD
85
sharpness 85
af 81
build 90
value 86
Viltrox AF 13mm f/1.4 STM
84
sharpness 84
af 80
build 90
value 86

Specs side-by-side

Tamron 20-40mm f/2.8 Di III VXD versus Viltrox AF 13mm f/1.4 STM — full spec comparison
Spec Tamron 20-40mm f/2.8 Di III VXD Viltrox AF 13mm f/1.4 STM

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

Viltrox AF 13mm f/1.4 STM

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

FAQ: Tamron 20-40mm f/2.8 Di III VXD vs Viltrox AF 13mm f/1.4 STM

Which is better, Tamron 20-40mm f/2.8 Di III VXD or Viltrox AF 13mm f/1.4 STM? +

Tamron 20-40mm f/2.8 Di III VXD scores 85 on our weighted rubric — ahead by 1. 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 Viltrox AF 13mm f/1.4 STM worth the price? +

At $449, Viltrox AF 13mm f/1.4 STM delivers a Specdex score of 84 — strongest in build.

Does Tamron 20-40mm f/2.8 Di III VXD or Viltrox AF 13mm f/1.4 STM 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.

Which is the better value, Tamron 20-40mm f/2.8 Di III VXD or Viltrox AF 13mm f/1.4 STM? +

Viltrox AF 13mm f/1.4 STM — more score per dollar ($449 vs $699). Specdex score per dollar at MSRP.