Panasonic LUMIX S 18mm f/1.8 vs Sigma 20mm f/2 DG DN Contemporary (L-mount)
The bottom line
These cover different focal lengths — the Panasonic LUMIX S 18mm f/1.8 is 18mm, the Sigma 20mm f/2 DG DN Contemporary (L-mount) is 20mm — so they're not really substitutes. Pick by the field of view you actually need: the Panasonic LUMIX S 18mm f/1.8 for wide-angle, the Sigma 20mm f/2 DG DN Contemporary (L-mount) for wide-angle.
Choose the Panasonic LUMIX S 18mm f/1.8 if…
- ✓You value portability — at 220g (7.8 oz) it's lighter than the 370g (13.1 oz) alternative for travel and all-day carry.
Choose the Sigma 20mm f/2 DG DN Contemporary (L-mount) if…
- ✓You work outdoors — it's weather-sealed against dust and moisture; the other isn't.
Where they differ
- ›Aperture: the Panasonic LUMIX S 18mm f/1.8 opens to f/1.8 vs the Sigma 20mm f/2 DG DN Contemporary (L-mount)'s f/2 — more light and shallower depth-of-field.
- ›Focal range: Panasonic LUMIX S 18mm f/1.8 is 18mm, Sigma 20mm f/2 DG DN Contemporary (L-mount) is 20mm — different framing and reach.
- ›Weight: the Panasonic LUMIX S 18mm f/1.8 is 220g (7.8 oz) vs 370g (13.1 oz) — you'll feel the difference handheld.
- ›Durability: the Sigma 20mm f/2 DG DN Contemporary (L-mount) is weather-sealed; the other isn't.
Frequently asked
Is the Panasonic LUMIX S 18mm f/1.8 or the Sigma 20mm f/2 DG DN Contemporary (L-mount) better?
These cover different focal lengths — the Panasonic LUMIX S 18mm f/1.8 is 18mm, the Sigma 20mm f/2 DG DN Contemporary (L-mount) is 20mm — so they're not really substitutes. Pick by the field of view you actually need: the Panasonic LUMIX S 18mm f/1.8 for wide-angle, the Sigma 20mm f/2 DG DN Contemporary (L-mount) for wide-angle.
Who should choose the Panasonic LUMIX S 18mm f/1.8?
Choose the Panasonic LUMIX S 18mm f/1.8 if you value portability — at 220g (7.8 oz) it's lighter than the 370g (13.1 oz) alternative for travel and all-day carry.
Who should choose the Sigma 20mm f/2 DG DN Contemporary (L-mount)?
Choose the Sigma 20mm f/2 DG DN Contemporary (L-mount) if you work outdoors — it's weather-sealed against dust and moisture; the other isn't.
What is the main difference between the Panasonic LUMIX S 18mm f/1.8 and the Sigma 20mm f/2 DG DN Contemporary (L-mount)?
Aperture: the Panasonic LUMIX S 18mm f/1.8 opens to f/1.8 vs the Sigma 20mm f/2 DG DN Contemporary (L-mount)'s f/2 — more light and shallower depth-of-field.
| Product | ||
|---|---|---|
| Optical Design | ||
| Focal Length | 18mm | 20mm |
| Lens Type | Prime | Prime |
| Optical Elements | 13 | 13 |
| Optical Groups | 12 | 11 |
| Aperture & Iris | ||
| Maximum Aperture | f/1.8 | f/2 |
| Minimum Aperture | f/16 | f/16 |
| Aperture Blades | 9 | 9 |
| Rounded Aperture | Yes | Yes |
| Coverage & Angle | ||
| Format Coverage | Full-Frame | Full-Frame |
| Lens Mount | L-Mount | L-Mount |
| Angle of View | 100° | 94° |
| 35mm Equivalent | − | − |
| Focus | ||
| Autofocus | Yes | Yes |
| Focus Motor | Stepping | HLA |
| Focus Limiter | No | No |
| AF/MF Switch | Yes | Yes |
| Min Focus Distance | 18 cm | 22 cm |
| Max Magnification | 0.2x | 0.19x |
| Stabilization & Video | ||
| Optical Stabilization | No | No |
| Aperture Ring | No | Yes |
| Declickable Aperture | No | Yes |
| Parfocal | No | No |
| Internal Zoom | No | No |
| General | ||
| Price (MSRP) | $499 | $549 |
| Filter Size | 67mm | 67mm |
| Diameter | 73mm | 74.8mm |
| Length | 69mm | 90.5mm |
| Weight | 220g (7.8 oz) | 370g (13.1 oz) |
| Weather Sealed | No | Yes |
| Tripod Collar | No | No |
