Canon RF45mm F1.2 STMvsSigma 18-50mm F2.8 DC DN
RF45mm F1.2 STM
45mm / F1.2
—
18-50mm F2.8 DC DN
18-50mm / F2.8
27-75mm 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
When the 18-50mm F2.8 DC DN suits you better
- Weight46g lighter, so easier to carry
- Zoom rangeCovers 18-50mm in a single lens
- 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
- 18-50mm F2.8 DC DN74.5mm long × 69.2mm diameter
Specifications compared
| Specification | Canon RF45mm F1.2 STM | Sigma 18-50mm F2.8 DC DN | Difference |
|---|---|---|---|
| Focal length (wide) | 45mm | 18mm | +27mm |
| Focal length (tele) | 45mm | 50mm | −5mm |
| 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 | — | No data |
| Max magnification | 0.13× | — | No data |
| Aperture blades | 9blades | — | No data |
| Weight | 346g | 300g | +46g |
| Length | 75mm | 74.5mm | +0.5mm |
| Diameter | 78mm | 69.2mm | +8.8mm |
| Filter size | 67mm | 55mm | +12mm |
| Released | 2025 | 2024 | +1year |
| Stabilization | No | No | — |
| Weather sealing | No | Yes | No |
| Macro | No | No | — |
| Autofocus | Yes | Yes | — |
The difference column reads as RF45mm F1.2 STM relative to 18-50mm F2.8 DC DN.The highlighted cell is the better side for that specification.
Check prices
RF45mm F1.2 STM
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18-50mm F2.8 DC DN
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RF45mm F1.2 STM in detail18-50mm F2.8 DC DN in detailAll RF mount lenses