Tamron
Tamron 20-40mm f/2.8 Di III VXD
Prime/zoom
85
/ 100
From $699
VS
Canon RF 50mm f/1.2L USM wins by 11
Canon
Canon RF 50mm f/1.2L USM
Full-frame · 950 g · Pro portrait
96
/ 100
From $2,299
Specdex verdict
Canon RF 50mm f/1.2L 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 50mm f/1.2L USM at 96. That puts Canon RF 50mm f/1.2L 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 50mm f/1.2L USM if…
- ✓Breathtaking bokeh
- ✓Sharp wide open
- ✓Weather-sealed L build
Score breakdown
Tamron 20-40mm f/2.8 Di III VXD
85 sharpness 85
af 81
build 90
value 86
Canon RF 50mm f/1.2L USM
96 sharpness 98
af 94
build 98
value 82
Specs side-by-side
Spec
Tamron 20-40mm f/2.8 Di III VXD
Canon RF 50mm f/1.2L USM
Mount
—
Canon RF
Aperture
—
f/1.2
Weight
—
950 g
Filter size
—
77 mm
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 50mm f/1.2L USM
Pros
- +Breathtaking bokeh
- +Sharp wide open
- +Weather-sealed L build
Cons
- −Heavy at 950 g
- −Expensive
- −Breathing present
FAQ: Tamron 20-40mm f/2.8 Di III VXD vs Canon RF 50mm f/1.2L USM
Which is better, Tamron 20-40mm f/2.8 Di III VXD or Canon RF 50mm f/1.2L USM? +
Canon RF 50mm f/1.2L 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 50mm f/1.2L USM worth the price? +
At $2,299, Canon RF 50mm f/1.2L USM delivers a Specdex score of 96 — strongest in sharpness.
Does Tamron 20-40mm f/2.8 Di III VXD or Canon RF 50mm f/1.2L 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.