Canon
RF 135mm F1.8 L IS USM
Canon RF Mount
RF 135mm F1.8 L IS USM — 135mm f/1.8 for Canon RF, a popular choice in the canon lineup.
$2,099
Launch priceReleased Aug 2023
Canon
RF 50mm F1.8 STM
Canon RF Mount
The affordable nifty fifty for RF — compact, sharp, and perfect for beginners exploring prime lenses.
$199
Launch priceReleased Nov 2020
RF 135mm F1.8 L IS USM is 2.8 years newer.
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Wins
RF 135mm F1.8 L IS USM
Wins
RF 50mm F1.8 STM
2 categories tied
Which would you choose?
TL;DR — Key differences
- ARF 135mm F1.8 L IS USM has higher OIS effectiveness (5.5 stops vs 0 stops)
- BRF 50mm F1.8 STM has lower Weight (160 g vs 935 g)
- BRF 50mm F1.8 STM has lower Length (41 mm vs 130.4 mm)
- BRF 50mm F1.8 STM has lower Min focus distance (30 cm vs 70 cm)
- BRF 50mm F1.8 STM has lower Diameter (70 mm vs 89 mm)
Key specs at a glance
Size and weight, to scale
📸 Snap this lens size diff to shareRF 135mm F1.8 L IS USM
⌀89 × 130 mm
935 g (2.06 lb / 32.98 oz)
Credit card
85.6 × 54 mm
for scale
RF 50mm F1.8 STM
⌀70 × 41 mm
160 g (0.35 lb / 5.64 oz)
RF 135mm F1.8 L IS USM is 89mm longer and 19mm wider than RF 50mm F1.8 STM.
RF 135mm F1.8 L IS USM is 775 g heavier than RF 50mm F1.8 STM.
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 135mm F1.8 L IS USM
- ✓
Special elements
Adds 1 UD, 1 Aspherical
- ✓
OIS effectiveness
5.5 stops vs 0 stops — higher is better
- ✓
Optical stabilization
Only RF 135mm F1.8 L IS USM supports it
- ✓
Weather sealing
Only RF 135mm F1.8 L IS USM supports it
- ✓
Custom function button
Only RF 135mm F1.8 L IS USM supports it
- ✓
Max magnification
0.29 × vs 0.25 × — higher is better
Reasons to choose the RF 50mm F1.8 STM
- ✓
Weight
160 g vs 935 g — lower is better
- ✓
Length
41 mm vs 130.4 mm — lower is better
- ✓
Min focus distance
30 cm vs 70 cm — lower is better
- ✓
Diameter
70 mm vs 89 mm — lower is better
Shared specifications
Max aperture (Wide)
Both f/1.8
Max aperture (Tele)
Both f/1.8
Internal focus
Both support internal focus
Control ring
Both support control ring
Pros & cons at a glance
Editorially curated highlights and trade-offs.
RF 135mm F1.8 L IS USM
Pros
- ✓Prime design typically delivers strong sharpness and lighter weight
- ✓Built-in optical image stabilization
- ✓Weather-sealed construction for outdoor shooting
Cons
- –Premium price point
- –Relatively heavy for extended handheld use
RF 50mm F1.8 STM
Pros
- ✓Incredible value at under $200
- ✓Very compact and lightweight (only 160g)
- ✓Sharp enough for most everyday photography
- ✓Silent STM motor ideal for video
Cons
- –Plastic build feels basic
- –No weather sealing
- –Narrow maximum aperture vs L-series primes
Decided which one is right for you?
Compare live prices for the RF 135mm F1.8 L IS USM and RF 50mm F1.8 STM at major authorized retailers.
Canon RF 135mm F1.8 L IS USM
Canon RF 50mm F1.8 STM
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Full specifications
✓ = category winner
Specs sourced from manufacturer data. Use-case scores algorithmically derived. Last reviewed June 2026.