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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
Nikon Z 100-400mm f/4.5-5.6 VR S wins by 6
Nikon Z 100-400mm f/4.5-5.6 VR S — Prime/Zoom
Nikon

Nikon Z 100-400mm f/4.5-5.6 VR S

Prime/Zoom

91
/ 100
From $2,699
Specdex verdict

Nikon Z 100-400mm f/4.5-5.6 VR S takes it — here’s why.

In our weighted Specdex score, Tamron 20-40mm f/2.8 Di III VXD lands at 85 and Nikon Z 100-400mm f/4.5-5.6 VR S at 91. That puts Nikon Z 100-400mm f/4.5-5.6 VR S ahead by 6 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 Nikon Z 100-400mm f/4.5-5.6 VR S if…

  • ✓Fast aperture
  • ✓Quiet autofocus
  • ✓Weather-sealed (most)
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Winner by scenario

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

Build

Tamron 20-40mm f/2.8 Di III VXD

Compared on the build sub-score

Tamron 20-40mm f/2.8 Di III VXD leads on build (90 vs 88).

Sharpness

Nikon Z 100-400mm f/4.5-5.6 VR S

Compared on the sharpness sub-score

Nikon Z 100-400mm f/4.5-5.6 VR S leads on sharpness (91 vs 85).

Autofocus

Nikon Z 100-400mm f/4.5-5.6 VR S

Compared on the autofocus sub-score

Nikon Z 100-400mm f/4.5-5.6 VR S leads on af (89 vs 81).

Value for money

Tamron 20-40mm f/2.8 Di III VXD

Specdex score per dollar at MSRP

Tamron 20-40mm f/2.8 Di III VXD more score per dollar ($699 vs $2,699).

Tamron 20-40mm f/2.8 Di III VXD 85
vs
91 Nikon Z 100-400mm f/4.5-5.6 VR S

Score breakdown

Tamron 20-40mm f/2.8 Di III VXD
85
sharpness 85
af 81
build 90
value 86
Nikon Z 100-400mm f/4.5-5.6 VR S
91
sharpness 91
af 89
build 88
value 85

Specs side-by-side

Tamron 20-40mm f/2.8 Di III VXD versus Nikon Z 100-400mm f/4.5-5.6 VR S — full spec comparison
Spec Tamron 20-40mm f/2.8 Di III VXD Nikon Z 100-400mm f/4.5-5.6 VR S

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

Nikon Z 100-400mm f/4.5-5.6 VR S

Pros
  • +Fast aperture
  • +Quiet autofocus
  • +Weather-sealed (most)
Cons
  • −Mount-specific
  • −Weight varies
  • −Price scales with quality

FAQ: Tamron 20-40mm f/2.8 Di III VXD vs Nikon Z 100-400mm f/4.5-5.6 VR S

Which is better, Tamron 20-40mm f/2.8 Di III VXD or Nikon Z 100-400mm f/4.5-5.6 VR S? +

Nikon Z 100-400mm f/4.5-5.6 VR S scores 91 on our weighted rubric — ahead by 6. 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 Nikon Z 100-400mm f/4.5-5.6 VR S worth the price? +

At $2,699, Nikon Z 100-400mm f/4.5-5.6 VR S delivers a Specdex score of 91 — strongest in sharpness.

Does Tamron 20-40mm f/2.8 Di III VXD or Nikon Z 100-400mm f/4.5-5.6 VR S 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 better for build, Tamron 20-40mm f/2.8 Di III VXD or Nikon Z 100-400mm f/4.5-5.6 VR S? +

Tamron 20-40mm f/2.8 Di III VXD — leads on build (90 vs 88). Compared on the build sub-score.

Which is better for sharpness, Tamron 20-40mm f/2.8 Di III VXD or Nikon Z 100-400mm f/4.5-5.6 VR S? +

Nikon Z 100-400mm f/4.5-5.6 VR S — leads on sharpness (91 vs 85). Compared on the sharpness sub-score.