Sigma 17-40mm F1.8 DCvsTamron 17-70mm F/2.8 Di III-A VC RXD
17-40mm F1.8 DC
17-40mm / F1.8
26-60mm equiv.
—
17-70mm F/2.8 Di III-A VC RXD
17-70mm / F2.8
26-105mm equiv.
—
Which to choose
When the 17-40mm F1.8 DC suits you better
- Brightness1.3 stops brighter — better in low light and blurs the background more
When the 17-70mm F/2.8 Di III-A VC RXD suits you better
- Zoom rangeCovers 17-70mm in a single lens
- StabilizationHas stabilization
These points are derived mechanically from the numbers. How a lens actually renders does not show up in specifications, so look at samples before deciding.
Size compared
- 17-40mm F1.8 DC115.9mm long × 72.9mm diameter
- 17-70mm F/2.8 Di III-A VC RXD117.3mm long × 74.6mm diameter
Specifications compared
| Specification | Sigma 17-40mm F1.8 DC | Tamron 17-70mm F/2.8 Di III-A VC RXD | Difference |
|---|---|---|---|
| Focal length (wide) | 17mm | 17mm | — |
| Focal length (tele) | 40mm | 70mm | −30mm |
| Max aperture (wide) | F1.8 | F2.8 | 1.3 stops brighter |
| Max aperture (tele) | F1.8 | F2.8 | 1.3 stops brighter |
| Min focus distance | — | 19cm | No data |
| Weight | 560g | 530g | +30g |
| Length | 115.9mm | 117.3mm | −1.4mm |
| Diameter | 72.9mm | 74.6mm | −1.7mm |
| Filter size | 67mm | 67mm | — |
| Released | 2025 | 2026 | −1year |
| Stabilization | No | Yes | No |
| Weather sealing | Yes | Yes | — |
| Macro | No | No | — |
| Autofocus | Yes | Yes | — |
The difference column reads as 17-40mm F1.8 DC relative to 17-70mm F/2.8 Di III-A VC RXD.The highlighted cell is the better side for that specification.
Check prices
17-40mm F1.8 DC
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17-70mm F/2.8 Di III-A VC RXD
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17-40mm F1.8 DC in detail17-70mm F/2.8 Di III-A VC RXD in detailAll RF mount lenses