Samyang 20mm F1.8 ED AS UMC vs Sirui Swift 20mm F2.4
The Samyang is brighter (f/1.8 vs f/2.4). The Sirui is 318g lighter, has autofocus and is weather sealed.
Key differences
- The Sirui is 318g lighter (207g vs 525g).
- The Samyang is faster: f/1.8 vs f/2.4 (≈0.8 stops more light).
- The Samyang is manual focus only.
- For close-ups the Samyang reaches 0.15× vs 0.14×.
Which to choose
- 20mm F1.8 ED AS UMC
Choose it for:
- +The brightest aperture: f/1.8, about 0.8 stop more light
- Swift 20mm F2.4
Choose it for:
- +The lightest option: 207g, 318g less than the next
- +Autofocus
- +Weather sealing
Computed from published specs, confirmed launch prices and, where every lens has at least two reviews, review scores.
Samyang/Rokinon
20mm F1.8 ED AS UMC
Sirui
Swift 20mm F2.4
- Mount
- Sony E (FE)
- Sony E (FE)
- Focal length
- 20mm
- 20mm
- Max aperture
- F1.8◆
- F2.4
- Weight
- 525g
- 207g◆
- Dimensions ⌀ × L
- 83.0 × 114.4mm
- 69.5 × 62.3mm
- Volume
- 619 cm³
- 236 cm³◆
- Density
- 0.85 g/cm³
- 0.88 g/cm³
- Filter thread
- ⌀77mm
- ⌀58mm
- Min focus
- 0.20m
- 0.20m
- Max magnification
- ≈0.15×◆
- 0.14×
- Elements / groups
- 13 / 12
- 11 / 9
- Aperture blades
- 7
- 9◆
- Focus drive
- Manual Helicoid
- STM
- Stabilisation
- —
- —
- Weather sealed
- —
- Yes
- Aperture ring
- Yes
- Yes
- Released
- 2016
- 2026
- MSRP (USD)
- Unconfirmed
- $149
- Sharpness
- 7.8
- —
- Bokeh Rendering
- —
- —
- Autofocus Speed
- MF
- —
- Flare Resistance
- 7.8
- —
- Build / Sealing
- 6.8
- —
- Value / Size
- 8.4
- —
Performance overlay
- 20mm F1.8 ED AS UMC
- Swift 20mm F2.4
◆ marks the best value in a row. Scores are 0–10 editorial ratings.