It's a trade-off
The Sigma 18-50mm DC DN offers a lighter body (235g less) and closer minimum focusing, while the Tamron 17-70mm f/2.8 Di III-A VC RXD offers a lower price (£95 less) and built-in stabilization. Both share a compatible lens mount.
Our take: If you're unsure, the Tamron 17-70mm f/2.8 Di III-A VC RXD is the safer value pick — step up to the Sigma 18-50mm DC DN only if you want a lighter body (235g less) and closer minimum focusing.
It really comes down to weight versus price — pick the one whose strengths match how you shoot.
…if you want:
| Sigma 18-50mm DC DN | Tamron 17-70mm f/2.8 Di III-A VC RXD |
|---|---|
| Price £475on Amazon | Price £380on Amazon |
| BrandSigma |
Lenny's verdictBETALenny couldn't answer just now — it's usually temporary.
…if you want:
| BrandTamron |
Sensor Format
| Sensor Format
|
Mount
| Mount
|
| CategoryFisheye | CategoryUltra Wide |
| Use Case EverydayLandscapeLow LightStreetTravel | Use Case EverydayTravelEventLow LightVideography |
| Focal Length18mm - 50mm | Focal Length17mm - 70mm |
| Angle of View74° - 35° | Angle of View79° - 23° |
| Aperture f/2.8 (max)f/22 (min) | Aperture f/2.8 (max)f/22 (min) |
| Blades7 | Blades9 Smoother bokeh |
| Circular ApertureYes | Circular ApertureYes |
| Min Focus Distance0.12m Focuses closer | Min Focus Distance0.19m |
| Max Magnification0.2x | Max Magnification0.27x |
| Filter Diameter55mm | Filter Diameter67mm |
| Weight290g Lighter | Weight525g |
| StabilizationNo (relies on camera) | StabilizationYes Has stabilization |
| Auto FocusYes | Auto FocusYes |
| Release Date2021 | Release Date2020 |
| View full detailsSigma 18-50mm DC DN | View full detailsTamron 17-70mm f/2.8 Di III-A VC RXD |
