Canon RF45mm F1.2 STMvsTamron 17-70mm F/2.8 Di III-A VC RXD
RF45mm F1.2 STM
45mm / F1.2
—
17-70mm F/2.8 Di III-A VC RXD
17-70mm / F2.8
26-105mm equiv.
—
Which to choose
When the RF45mm F1.2 STM suits you better
- Brightness2.4 stops brighter — better in low light and blurs the background more
- Weight184g lighter, so easier to carry
When the 17-70mm F/2.8 Di III-A VC RXD suits you better
- Close focusFocuses as close as 19cm
- Zoom rangeCovers 17-70mm in a single lens
- StabilizationHas stabilization
- Weather sealingHas weather sealing
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
- RF45mm F1.2 STM75mm long × 78mm diameter
- 17-70mm F/2.8 Di III-A VC RXD117.3mm long × 74.6mm diameter
Specifications compared
| Specification | Canon RF45mm F1.2 STM | Tamron 17-70mm F/2.8 Di III-A VC RXD | Difference |
|---|---|---|---|
| Focal length (wide) | 45mm | 17mm | +28mm |
| Focal length (tele) | 45mm | 70mm | −25mm |
| Max aperture (wide) | F1.2 | F2.8 | 2.4 stops brighter |
| Max aperture (tele) | F1.2 | F2.8 | 2.4 stops brighter |
| Min aperture | F16 | — | No data |
| Min focus distance | 45cm | 19cm | +0.26m |
| Max magnification | 0.13× | — | No data |
| Aperture blades | 9blades | — | No data |
| Weight | 346g | 530g | −184g |
| Length | 75mm | 117.3mm | −42.3mm |
| Diameter | 78mm | 74.6mm | +3.4mm |
| Filter size | 67mm | 67mm | — |
| Released | 2025 | 2026 | −1year |
| Stabilization | No | Yes | No |
| Weather sealing | No | Yes | No |
| Macro | No | No | — |
| Autofocus | Yes | Yes | — |
The difference column reads as RF45mm F1.2 STM relative to 17-70mm F/2.8 Di III-A VC RXD.The highlighted cell is the better side for that specification.
Check prices
RF45mm F1.2 STM
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17-70mm F/2.8 Di III-A VC RXD
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RF45mm F1.2 STM in detail17-70mm F/2.8 Di III-A VC RXD in detailAll RF mount lenses