Sony E-Mount
Tamron 17-70mm F2.8 Di III-A VC RXD vs Sigma 18-50mm F2.8 DC DN Contemporary
Two APS-C zooms for Sony E with constant f/2.8, built around different ideas. The Tamron 17-70mm f/2.8 Di III-A VC RXD (market launch January 2021) runs from 17 to 70 mm (about 26 to 105 mm in full-frame terms) and has optical image stabilization (VC). It weighs 525 g, is 119.3 mm long and takes 67 mm filters.
The Sigma 18-50mm f/2.8 DC DN Contemporary (announced October 2021) ends at 50 mm (about 75 mm full-frame equivalent) and has no stabilization of its own. It weighs 290 g, is 76.5 mm long and takes 55 mm filters. The Sigma focuses from 12.1 cm at 18 mm (maximum magnification 1:2.8), the Tamron from 19 cm at 17 mm (1:4.8).
Key data at a glance
- Tamron 17-70mm: 17 to 70 mm, about 26 to 105 mm full-frame equivalent, stabilized, 525 g, 67 mm filters.
- Sigma 18-50mm: 18 to 50 mm, about 27 to 75 mm full-frame equivalent, no stabilizer, 290 g, 55 mm filters.
Key differences
- Focal length: 17-70 mm on the Tamron 17-70mm F2.8 Di III-A VC RXD, 18-50 mm on the Sigma 18-50mm F2.8 DC DN Contemporary.
- Full-frame equivalent (crop factor 1.5): 26-105 mm on the Tamron 17-70mm F2.8 Di III-A VC RXD, 27-75 mm on the Sigma 18-50mm F2.8 DC DN Contemporary.
- The Sigma 18-50mm F2.8 DC DN Contemporary is 235 g lighter (290 g vs 525 g).
- The Sigma 18-50mm F2.8 DC DN Contemporary is 43 mm shorter.
- The Sigma 18-50mm F2.8 DC DN Contemporary is narrower: 61.6 mm instead of 74.6 mm in diameter.
- Filter thread: 67 mm on the Tamron 17-70mm F2.8 Di III-A VC RXD, 55 mm on the Sigma 18-50mm F2.8 DC DN Contemporary.
- The Sigma 18-50mm F2.8 DC DN Contemporary focuses closer: from 12.1 cm instead of 19 cm.
- Maximum magnification: 1:2.8 on the Sigma 18-50mm F2.8 DC DN Contemporary, 1:4.8 on the Tamron 17-70mm F2.8 Di III-A VC RXD.
- Only the Tamron 17-70mm F2.8 Di III-A VC RXD has optical image stabilization.
- Market launch or announcement: January 2021 for the Tamron 17-70mm F2.8 Di III-A VC RXD, October 2021 (announced) for the Sigma 18-50mm F2.8 DC DN Contemporary.
Minimum focus distance by focal length
Manufacturer figures, measured from the sensor plane. On zooms the limit changes with the focal length.
- Tamron 17-70mm F2.8 Di III-A VC RXD
- 19 cm at 17 mm 路 39 cm at 70 mm
- Sigma 18-50mm F2.8 DC DN Contemporary
- 12.1 cm at 18 mm 路 30 cm at 50 mm
Specs side by side
The key specs of both lenses side by side.
| Lens | Tamron 17-70mm F2.8 Di III-A VC RXD | Sigma 18-50mm F2.8 DC DN Contemporary |
|---|---|---|
| Focal length | 17-70 mm | 18-50 mm |
| Max. aperture | f/2.8 | f/2.8 |
| Weight | 525 g | 290 g |
| Filter diameter | 67 mm | 55 mm |
| Min. focus distance | 19 cm | 12.1 cm |
| Length | 119.3 mm | 76.5 mm |
| Autofocus | yes | yes |
| Image stabilization | yes | no |
Size comparison
- 1 Tamron 17-70mm F2.8 Di III-A VC RXD 119.3 脳 74.6 mm 路 525 g
- 2 Sigma 18-50mm F2.8 DC DN Contemporary 76.5 脳 61.6 mm 路 290 g
Schematic silhouettes. Length and diameter are manufacturer figures, drawn at the same scale for all lenses.
Open in the size comparisonFeatures named by the manufacturers
Features the manufacturer states explicitly.
Sigma 18-50mm F2.8 DC DN Contemporary
- Weather protection
- Internal focusing
Compatible cameras
Both lenses fit Sony E-Mount cameras. The database lists 52 bodies: 27 full frame (in APS-C mode), 25 APS-C.
Camera list and adapters for the Tamron 17-70mm F2.8 Di III-A VC RXDCamera list and adapters for the Sigma 18-50mm F2.8 DC DN Contemporary
More lenses in this class
Sony E-Mount lenses with a similar focal length and aperture to the two compared here.
- Sony E 16-55mm F2.8 G 16-55 mm 路 f/2.8 Sony E 16-55mm F2.8 G vs Sigma 18-50mm F2.8 DC DN Contemporary Compare all threeSony E 16-55mm F2.8 G
- Sony E 18-55mm F3.5-5.6 OSS 18-55 mm 路 f/3.5-5.6 Compare all threeSony E 18-55mm F3.5-5.6 OSS
- Sony E 16-50mm F3.5-5.6 PZ OSS 16-50 mm 路 f/3.5-5.6 Compare all threeSony E 16-50mm F3.5-5.6 PZ OSS
- Sony E 16-50mm F3.5-5.6 PZ OSS II 16-50 mm 路 f/3.5-5.6 Compare all threeSony E 16-50mm F3.5-5.6 PZ OSS II
Frequently asked questions about this comparison
Which is lighter, the Tamron 17-70mm F2.8 Di III-A VC RXD or the Sigma 18-50mm F2.8 DC DN Contemporary?
The Sigma 18-50mm F2.8 DC DN Contemporary is lighter at 290 g than the Tamron 17-70mm F2.8 Di III-A VC RXD at 525 g, a difference of 235 g.
Which is faster, the Tamron 17-70mm F2.8 Di III-A VC RXD or the Sigma 18-50mm F2.8 DC DN Contemporary?
Both have the same maximum aperture: f/2.8.
What filter size do the Tamron 17-70mm F2.8 Di III-A VC RXD and the Sigma 18-50mm F2.8 DC DN Contemporary use?
The Tamron 17-70mm F2.8 Di III-A VC RXD takes 67 mm filters, the Sigma 18-50mm F2.8 DC DN Contemporary takes 55 mm.
Do the Tamron 17-70mm F2.8 Di III-A VC RXD and the Sigma 18-50mm F2.8 DC DN Contemporary have image stabilization?
Only the Tamron 17-70mm F2.8 Di III-A VC RXD has optical image stabilization.
Do the Tamron 17-70mm F2.8 Di III-A VC RXD and the Sigma 18-50mm F2.8 DC DN Contemporary fit the same cameras?
Yes, both fit Sony E-Mount cameras.