Sigma 17mm f/4 DG DN Contemporary vs Sony FE 40mm f/2.5 G
The bottom line
These cover different focal lengths — the Sigma 17mm f/4 DG DN Contemporary is 17mm, the Sony FE 40mm f/2.5 G is 40mm — so they're not really substitutes. Pick by the field of view you actually need: the Sigma 17mm f/4 DG DN Contemporary for wide-angle, the Sony FE 40mm f/2.5 G for standard.
Choose the Sigma 17mm f/4 DG DN Contemporary if…
- ✓You shoot wide — it starts at 17mm vs 40mm for landscapes, interiors and architecture.
- ✓You like close-focus work — 0.5x magnification vs 0.23x.
Choose the Sony FE 40mm f/2.5 G if…
- ✓You want more light and background blur — f/2.5 is faster than f/4, better for low light and subject separation.
- ✓You need more reach — it goes to 40mm vs 17mm for distant subjects, wildlife and sport.
- ✓You value portability — at 173g (6.1 oz) it's lighter than the 225g (7.9 oz) alternative for travel and all-day carry.
- ✓You work outdoors — it's weather-sealed against dust and moisture; the other isn't.
Where they differ
- ›Aperture: the Sony FE 40mm f/2.5 G opens to f/2.5 vs the Sigma 17mm f/4 DG DN Contemporary's f/4 — more light and shallower depth-of-field.
- ›Focal range: Sigma 17mm f/4 DG DN Contemporary is 17mm, Sony FE 40mm f/2.5 G is 40mm — different framing and reach.
- ›Close-up: the Sigma 17mm f/4 DG DN Contemporary reaches 0.5x magnification vs 0.23x — more for close-up and macro work.
- ›Durability: the Sony FE 40mm f/2.5 G is weather-sealed; the other isn't.
Frequently asked
Is the Sigma 17mm f/4 DG DN Contemporary or the Sony FE 40mm f/2.5 G better?
These cover different focal lengths — the Sigma 17mm f/4 DG DN Contemporary is 17mm, the Sony FE 40mm f/2.5 G is 40mm — so they're not really substitutes. Pick by the field of view you actually need: the Sigma 17mm f/4 DG DN Contemporary for wide-angle, the Sony FE 40mm f/2.5 G for standard.
Who should choose the Sigma 17mm f/4 DG DN Contemporary?
Choose the Sigma 17mm f/4 DG DN Contemporary if you shoot wide — it starts at 17mm vs 40mm for landscapes, interiors and architecture. 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 want more light and background blur — f/2.5 is faster than f/4, better for low light and subject separation. Choose it if you need more reach — it goes to 40mm vs 17mm for distant subjects, wildlife and sport. Choose it if you value portability — at 173g (6.1 oz) it's lighter than the 225g (7.9 oz) alternative for travel and all-day carry. Choose it if you work outdoors — it's weather-sealed against dust and moisture; the other isn't.
What is the main difference between the Sigma 17mm f/4 DG 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 17mm f/4 DG DN Contemporary's f/4 — more light and shallower depth-of-field.
| Product | ||
|---|---|---|
| Optical Design | ||
| Focal Length | 17mm | 40mm |
| Lens Type | Prime | Prime |
| Optical Elements | 10 | 8 |
| Optical Groups | 8 | 7 |
| Aperture & Iris | ||
| Maximum Aperture | f/4 | f/2.5 |
| Minimum Aperture | f/22 | f/22 |
| Aperture Blades | 9 | 9 |
| Rounded Aperture | Yes | Yes |
| Coverage & Angle | ||
| Format Coverage | Full-Frame | Full-Frame |
| Lens Mount | Sony E | Sony E |
| Angle of View | 104° | 57° |
| 35mm Equivalent | − | − |
| 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) | $549 | $599 |
| Filter Size | 55mm | 49mm |
| Diameter | 62mm | 68mm |
| Length | 61.4mm | 45.5mm |
| Weight | 225g (7.9 oz) | 173g (6.1 oz) |
| Weather Sealed | No | Yes |
| Tripod Collar | No | No |
