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Canon RF 600mm f/11 IS STM — Prime/Zoom
Canon

Canon RF 600mm f/11 IS STM

Prime/Zoom

82
/ 100
From $699
VS
Viltrox AF 20mm f/2.8 Full-Frame — Prime/zoom
Viltrox

Viltrox AF 20mm f/2.8 Full-Frame

Prime/zoom

82
/ 100
From $169
Specdex verdict

Dead heat — it comes down to priorities.

In our weighted Specdex score, Canon RF 600mm f/11 IS STM lands at 82 and Viltrox AF 20mm f/2.8 Full-Frame at 82. With scores tied, the decision hinges on which sub-scores matter most to you.

Pick Canon RF 600mm f/11 IS STM if…

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

Pick Viltrox AF 20mm f/2.8 Full-Frame 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

Viltrox AF 20mm f/2.8 Full-Frame

Compared on the build sub-score

Viltrox AF 20mm f/2.8 Full-Frame leads on build (90 vs 88).

Sharpness

Tie

Compared on the sharpness sub-score

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

Autofocus

Canon RF 600mm f/11 IS STM

Compared on the autofocus sub-score

Canon RF 600mm f/11 IS STM leads on af (80 vs 78).

Value for money

Viltrox AF 20mm f/2.8 Full-Frame

Specdex score per dollar at MSRP

Viltrox AF 20mm f/2.8 Full-Frame more score per dollar ($169 vs $699).

Canon RF 600mm f/11 IS STM 82
vs
82 Viltrox AF 20mm f/2.8 Full-Frame

Score breakdown

Canon RF 600mm f/11 IS STM
82
sharpness 82
af 80
build 88
value 85
Viltrox AF 20mm f/2.8 Full-Frame
82
sharpness 82
af 78
build 90
value 86

Specs side-by-side

Canon RF 600mm f/11 IS STM versus Viltrox AF 20mm f/2.8 Full-Frame — full spec comparison
Spec Canon RF 600mm f/11 IS STM Viltrox AF 20mm f/2.8 Full-Frame

Canon RF 600mm f/11 IS STM

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

Viltrox AF 20mm f/2.8 Full-Frame

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

FAQ: Canon RF 600mm f/11 IS STM vs Viltrox AF 20mm f/2.8 Full-Frame

Which is better, Canon RF 600mm f/11 IS STM or Viltrox AF 20mm f/2.8 Full-Frame? +

Both score 82 on our weighted rubric — tied. Your best pick depends on the sub-scores above.

Is Canon RF 600mm f/11 IS STM worth the price? +

At $699, Canon RF 600mm f/11 IS STM delivers a Specdex score of 82 — strongest in build.

Is Viltrox AF 20mm f/2.8 Full-Frame worth the price? +

At $169, Viltrox AF 20mm f/2.8 Full-Frame delivers a Specdex score of 82 — strongest in build.

Does Canon RF 600mm f/11 IS STM or Viltrox AF 20mm f/2.8 Full-Frame 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 600mm f/11 IS STM or Viltrox AF 20mm f/2.8 Full-Frame? +

Viltrox AF 20mm f/2.8 Full-Frame — leads on build (90 vs 88). Compared on the build sub-score.

Which is better for autofocus, Canon RF 600mm f/11 IS STM or Viltrox AF 20mm f/2.8 Full-Frame? +

Canon RF 600mm f/11 IS STM — leads on af (80 vs 78). Compared on the autofocus sub-score.