Canon
RF 10-20mm F4 L IS USM
Canon RF Mount
RF 10-20mm F4 L IS USM — 10–20mm f/4 for Canon RF, a popular choice in the canon lineup.
$2,299
Launch priceReleased Oct 2023
Canon
RF 85mm F1.2L USM
Canon RF Mount
The definitive portrait prime for RF — f/1.2 aperture delivers unmatched subject separation and dreamy backgrounds.
$2,699
Launch priceReleased Feb 2019
RF 10-20mm F4 L IS USM is 4.7 years newer.
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Wins
RF 10-20mm F4 L IS USM
Wins
RF 85mm F1.2L USM
Which would you choose?
TL;DR — Key differences
- ARF 10-20mm F4 L IS USM has higher OIS effectiveness (5.5 stops vs 0 stops)
- ARF 10-20mm F4 L IS USM has lower Min focus distance (24 cm vs 85 cm)
- BRF 85mm F1.2L USM has lower Max aperture (Wide) (f/1.2 vs f/4)
- BRF 85mm F1.2L USM has lower Max aperture (Tele) (f/1.2 vs f/4)
- ARF 10-20mm F4 L IS USM has lower Weight (620 g vs 1195 g)
Key specs at a glance
Size and weight, to scale
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RF 10-20mm F4 L IS USM
⌀84 × 113 mm
620 g (1.37 lb / 21.87 oz)
Credit card
85.6 × 54 mm
for scale
RF 85mm F1.2L USM
⌀103 × 117 mm
1195 g (2.63 lb / 42.15 oz)
RF 10-20mm F4 L IS USM is 4mm shorter and 19mm narrower than RF 85mm F1.2L USM.
RF 10-20mm F4 L IS USM is 575 g lighter than RF 85mm F1.2L USM.
Diameter (⌀) is the maximum barrel width; length is measured from the mount to the front of the lens.
Use-case scoring
Which one for what?
Algorithmic scores from verified specs · 10 = best in class
Why pick one over the other
Reasons to choose the RF 10-20mm F4 L IS USM
- ✓
OIS effectiveness
5.5 stops vs 0 stops — higher is better
- ✓
Min focus distance
24 cm vs 85 cm — lower is better
- ✓
Special elements
Adds 2 UD, 1 Super UD
- ✓
Optical stabilization
Only RF 10-20mm F4 L IS USM supports it
- ✓
Custom function button
Only RF 10-20mm F4 L IS USM supports it
- ✓
Weight
620 g vs 1195 g — lower is better
- ✓
Diameter
83.6 mm vs 103 mm — lower is better
- ✓
Max magnification
0.17 × vs 0.12 × — higher is better
Reasons to choose the RF 85mm F1.2L USM
- ✓
Max aperture (Wide)
f/1.2 vs f/4 — lower is better
- ✓
Max aperture (Tele)
f/1.2 vs f/4 — lower is better
- ✓
Special elements
Adds 1 UD
Shared specifications
Internal focus
Both support internal focus
Weather sealing
Both support weather sealing
Control ring
Both support control ring
Pros & cons at a glance
Editorially curated highlights and trade-offs.
RF 10-20mm F4 L IS USM
Pros
- ✓Versatile zoom range covers multiple focal lengths in one lens
- ✓Built-in optical image stabilization
- ✓Weather-sealed construction for outdoor shooting
Cons
- –Premium price point
- –Slower maximum aperture limits low-light performance
RF 85mm F1.2L USM
Pros
- ✓Class-leading portrait focal length with f/1.2 aperture
- ✓Exceptional subject isolation and bokeh quality
- ✓Excellent eye-AF tracking on Canon R bodies
- ✓Premium L-series weather sealing
Cons
- –Very heavy (1195g) — tiring for handheld sessions
- –Expensive flagship pricing
- –No built-in stabilization
Decided which one is right for you?
Compare live prices for the RF 10-20mm F4 L IS USM and RF 85mm F1.2L USM at major authorized retailers.
Canon RF 10-20mm F4 L IS USM
Canon RF 85mm F1.2L USM
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Full specifications
✓ = category winner
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.