Lens comparison
Tamron 17-70mm F/2.8 Di III-A VC RXD vs Sigma 18-50mm F2.8 DC DN
Side by side on the Sony a6700: the view each gives, the weight with the camera and their sizes to one scale. No winner: the numbers that differ are the choice.
Side views to one scale from the makers' published sizes, mount on the left.
| Lens | Tamron 17-70mm F/2.8 Di III-A VC RXD | Sigma 18-50mm F2.8 DC DN Contemporary |
|---|---|---|
| Focal length | 17–70 mm | 18–50 mm |
| View on the a6700 | 26–105 mm equiv. | 27–75 mm equiv. |
| Maximum apertureSame | f/2.8 | f/2.8 |
| Stabilised | Yes | No |
| Made forSame | APS-C | APS-C |
| Weight | 525 g | 290 g |
| With the a6700 | 1,018 g | 783 g |
| Length × diameter | 119.3 × 74.6 mm | 76.5 × 61.6 mm |
| Filter | 67 mm | 55 mm |
| Closest focus | 19 cm | 12 cm |
| Magnification | 0.21x | 0.36x |
| Weather sealing | Yes | Not stated |
| FitSame | Fits and works | Fits and works |
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Questions
Which is lighter on the a6700?
Sigma 18-50mm F2.8 DC DN Contemporary: Tamron 17-70mm F/2.8 Di III-A VC RXD 1,018 g against Sigma 18-50mm F2.8 DC DN 783 g with the camera, battery and card.
Which one is sharper?
We do not test lenses, so we cannot say; read reviews from people who have used both. The table compares what the makers publish.
Facts checked 9 Oct 2026 against the makers' specification pages. How we check