Sigma 18-50mm f/2.8 DC DN Contemporary vs Sony FE 40mm f/2.5 G
The bottom line
The Sigma 18-50mm f/2.8 DC DN Contemporary is a zoom (18-50mm) and the Sony FE 40mm f/2.5 G is a 40mm prime. The zoom gives you framing flexibility from one lens; the prime trades that for a fixed focal length that's usually brighter (f/2.5 vs f/2.8) and lighter to carry. Choose flexibility or a fast single focal length.
Choose the Sigma 18-50mm f/2.8 DC DN Contemporary if…
- ✓You shoot wide — it starts at 18mm vs 40mm for landscapes, interiors and architecture.
- ✓You want one-lens flexibility — a 18-50mm zoom covers what the fixed 40mm can't reframe.
- ✓You like close-focus work — 0.5x magnification vs 0.23x.
Choose the Sony FE 40mm f/2.5 G if…
- ✓You prefer a fast, compact single focal length — a 40mm prime over a zoom.
- ✓You value portability — at 173g (6.1 oz) it's lighter than the 290g (10.2 oz) alternative for travel and all-day carry.
Where they differ
- ›Aperture: the Sony FE 40mm f/2.5 G opens to f/2.5 vs the Sigma 18-50mm f/2.8 DC DN Contemporary's f/2.8 — more light and shallower depth-of-field.
- ›Focal range: Sigma 18-50mm f/2.8 DC DN Contemporary is 18-50mm, Sony FE 40mm f/2.5 G is 40mm — different framing and reach.
- ›Type: the Sigma 18-50mm f/2.8 DC DN Contemporary is a zoom (flexible framing), the Sony FE 40mm f/2.5 G a prime (one focal length, usually brighter and lighter).
- ›Close-up: the Sigma 18-50mm f/2.8 DC DN Contemporary reaches 0.5x magnification vs 0.23x — more for close-up and macro work.
- ›Weight: the Sony FE 40mm f/2.5 G is 173g (6.1 oz) vs 290g (10.2 oz) — you'll feel the difference handheld.
Frequently asked
Is the Sigma 18-50mm f/2.8 DC DN Contemporary or the Sony FE 40mm f/2.5 G better?
The Sigma 18-50mm f/2.8 DC DN Contemporary is a zoom (18-50mm) and the Sony FE 40mm f/2.5 G is a 40mm prime. The zoom gives you framing flexibility from one lens; the prime trades that for a fixed focal length that's usually brighter (f/2.5 vs f/2.8) and lighter to carry. Choose flexibility or a fast single focal length.
Who should choose the Sigma 18-50mm f/2.8 DC DN Contemporary?
Choose the Sigma 18-50mm f/2.8 DC DN Contemporary if you shoot wide — it starts at 18mm vs 40mm for landscapes, interiors and architecture. Choose it if you want one-lens flexibility — a 18-50mm zoom covers what the fixed 40mm can't reframe. Choose it if you like close-focus work — 0.5x magnification vs 0.23x.
Who should choose the Sony FE 40mm f/2.5 G?
Choose the Sony FE 40mm f/2.5 G if you prefer a fast, compact single focal length — a 40mm prime over a zoom. Choose it if you value portability — at 173g (6.1 oz) it's lighter than the 290g (10.2 oz) alternative for travel and all-day carry.
What is the main difference between the Sigma 18-50mm f/2.8 DC DN Contemporary and the Sony FE 40mm f/2.5 G?
Aperture: the Sony FE 40mm f/2.5 G opens to f/2.5 vs the Sigma 18-50mm f/2.8 DC DN Contemporary's f/2.8 — more light and shallower depth-of-field.
| Product | ||
|---|---|---|
| Optical Design | ||
| Focal Length | 18-50mm | 40mm |
| Lens Type | Zoom | Prime |
| Optical Elements | 13 | 8 |
| Optical Groups | 10 | 7 |
| Aperture & Iris | ||
| Maximum Aperture | f/2.8 | f/2.5 |
| Minimum Aperture | f/22 | f/22 |
| Aperture Blades | 9 | 9 |
| Rounded Aperture | Yes | Yes |
| Coverage & Angle | ||
| Format Coverage | APS-C | Full-Frame |
| Lens Mount | Sony E | Sony E |
| Angle of View | 76° – 32° | 57° |
| 35mm Equivalent | 27-75mm | − |
| Focus | ||
| Autofocus | Yes | Yes |
| Focus Motor | HLA | XD Linear |
| Focus Limiter | No | No |
| AF/MF Switch | Yes | Yes |
| Min Focus Distance | 13 cm | 25 cm |
| Max Magnification | 0.5x | 0.23x |
| Stabilization & Video | ||
| Optical Stabilization | No | No |
| Aperture Ring | Yes | Yes |
| Declickable Aperture | Yes | Yes |
| Parfocal | No | No |
| Internal Zoom | No | No |
| General | ||
| Price (MSRP) | $599 | $599 |
| Filter Size | 52mm | 49mm |
| Diameter | 65.4mm | 68mm |
| Length | 76.9mm | 45.5mm |
| Weight | 290g (10.2 oz) | 173g (6.1 oz) |
| Weather Sealed | Yes | Yes |
| Tripod Collar | No | No |
