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Canon RF 100-400mm f/5.6-8 — Prime/Zoom
Canon

Canon RF 100-400mm f/5.6-8

Prime/Zoom

84
/ 100
From $649
VS
Canon RF 15-35mm f/2.8L IS USM wins by 9
Canon RF 15-35mm f/2.8L IS USM — Prime/Zoom
Canon

Canon RF 15-35mm f/2.8L IS USM

Prime/Zoom

93
/ 100
From $2,299
Specdex verdict

Canon RF 15-35mm f/2.8L IS USM takes it — here’s why.

In our weighted Specdex score, Canon RF 100-400mm f/5.6-8 lands at 84 and Canon RF 15-35mm f/2.8L IS USM at 93. That puts Canon RF 15-35mm f/2.8L IS USM ahead by 9 points — a decisive margin driven mostly by its strengths in the categories below.

Pick Canon RF 100-400mm f/5.6-8 if…

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

Pick Canon RF 15-35mm f/2.8L IS USM if…

  • ✓Fast autofocus
  • ✓Weather-sealed
  • ✓Premium optics
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Winner by scenario

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

Build

Canon RF 15-35mm f/2.8L IS USM

Compared on the build sub-score

Canon RF 15-35mm f/2.8L IS USM leads on build (94 vs 88).

Sharpness

Canon RF 15-35mm f/2.8L IS USM

Compared on the sharpness sub-score

Canon RF 15-35mm f/2.8L IS USM leads on sharpness (93 vs 84).

Autofocus

Canon RF 15-35mm f/2.8L IS USM

Compared on the autofocus sub-score

Canon RF 15-35mm f/2.8L IS USM leads on af (92 vs 82).

Value for money

Canon RF 100-400mm f/5.6-8

Specdex score per dollar at MSRP

Canon RF 100-400mm f/5.6-8 more score per dollar ($649 vs $2,299).

Canon RF 100-400mm f/5.6-8 84
vs
93 Canon RF 15-35mm f/2.8L IS USM

Score breakdown

Canon RF 100-400mm f/5.6-8
84
sharpness 84
af 82
build 88
value 85
Canon RF 15-35mm f/2.8L IS USM
93
sharpness 93
af 92
build 94
value 84

Specs side-by-side

Canon RF 100-400mm f/5.6-8 versus Canon RF 15-35mm f/2.8L IS USM — full spec comparison
Spec Canon RF 100-400mm f/5.6-8 Canon RF 15-35mm f/2.8L IS USM

Canon RF 100-400mm f/5.6-8

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

Canon RF 15-35mm f/2.8L IS USM

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

FAQ: Canon RF 100-400mm f/5.6-8 vs Canon RF 15-35mm f/2.8L IS USM

Which is better, Canon RF 100-400mm f/5.6-8 or Canon RF 15-35mm f/2.8L IS USM? +

Canon RF 15-35mm f/2.8L IS USM scores 93 on our weighted rubric — ahead by 9. Your best pick depends on the sub-scores above.

Is Canon RF 100-400mm f/5.6-8 worth the price? +

At $649, Canon RF 100-400mm f/5.6-8 delivers a Specdex score of 84 — strongest in build.

Is Canon RF 15-35mm f/2.8L IS USM worth the price? +

At $2,299, Canon RF 15-35mm f/2.8L IS USM delivers a Specdex score of 93 — strongest in build.

Does Canon RF 100-400mm f/5.6-8 or Canon RF 15-35mm f/2.8L IS 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.

Which is better for build, Canon RF 100-400mm f/5.6-8 or Canon RF 15-35mm f/2.8L IS USM? +

Canon RF 15-35mm f/2.8L IS USM — leads on build (94 vs 88). Compared on the build sub-score.

Which is better for sharpness, Canon RF 100-400mm f/5.6-8 or Canon RF 15-35mm f/2.8L IS USM? +

Canon RF 15-35mm f/2.8L IS USM — leads on sharpness (93 vs 84). Compared on the sharpness sub-score.