Canon RF-S 18-45mm f/4.5-6.3 IS STM vs Sigma 30mm f/1.4 DC DN Contemporary (Canon RF)
The bottom line
The Canon RF-S 18-45mm f/4.5-6.3 IS STM is a zoom (18-45mm) and the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) is a 30mm prime. The zoom gives you framing flexibility from one lens; the prime trades that for a fixed focal length that's usually brighter (f/1.4 vs f/4.5) and lighter to carry. Choose flexibility or a fast single focal length.
Choose the Canon RF-S 18-45mm f/4.5-6.3 IS STM if…
- ✓You need more reach — it goes to 45mm vs 30mm for distant subjects, wildlife and sport.
- ✓You shoot wide — it starts at 18mm vs 30mm for landscapes, interiors and architecture.
- ✓You want one-lens flexibility — a 18-45mm zoom covers what the fixed 30mm can't reframe.
- ✓You shoot handheld or on an unstabilised body — it has optical stabilisation, the other doesn't.
Choose the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) if…
- ✓You want more light and background blur — f/1.4 is faster than f/4.5, better for low light and subject separation.
- ✓You prefer a fast, compact single focal length — a 30mm prime over a zoom.
Where they differ
- ›Aperture: the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) opens to f/1.4 vs the Canon RF-S 18-45mm f/4.5-6.3 IS STM's f/4.5 — more light and shallower depth-of-field.
- ›Focal range: Canon RF-S 18-45mm f/4.5-6.3 IS STM is 18-45mm, Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) is 30mm — different framing and reach.
- ›Type: the Canon RF-S 18-45mm f/4.5-6.3 IS STM is a zoom (flexible framing), the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) a prime (one focal length, usually brighter and lighter).
- ›Stabilisation: only the Canon RF-S 18-45mm f/4.5-6.3 IS STM has optical stabilisation — steadier handheld shots, especially on bodies without IBIS.
- ›Weight: the Canon RF-S 18-45mm f/4.5-6.3 IS STM is 149g (5.3 oz) vs 265g (9.3 oz) — you'll feel the difference handheld.
Frequently asked
Is the Canon RF-S 18-45mm f/4.5-6.3 IS STM or the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) better?
The Canon RF-S 18-45mm f/4.5-6.3 IS STM is a zoom (18-45mm) and the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) is a 30mm prime. The zoom gives you framing flexibility from one lens; the prime trades that for a fixed focal length that's usually brighter (f/1.4 vs f/4.5) and lighter to carry. Choose flexibility or a fast single focal length.
Who should choose the Canon RF-S 18-45mm f/4.5-6.3 IS STM?
Choose the Canon RF-S 18-45mm f/4.5-6.3 IS STM if you need more reach — it goes to 45mm vs 30mm for distant subjects, wildlife and sport. Choose it if you shoot wide — it starts at 18mm vs 30mm for landscapes, interiors and architecture. Choose it if you want one-lens flexibility — a 18-45mm zoom covers what the fixed 30mm can't reframe. Choose it if you shoot handheld or on an unstabilised body — it has optical stabilisation, the other doesn't.
Who should choose the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF)?
Choose the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) if you want more light and background blur — f/1.4 is faster than f/4.5, better for low light and subject separation. Choose it if you prefer a fast, compact single focal length — a 30mm prime over a zoom.
What is the main difference between the Canon RF-S 18-45mm f/4.5-6.3 IS STM and the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF)?
Aperture: the Sigma 30mm f/1.4 DC DN Contemporary (Canon RF) opens to f/1.4 vs the Canon RF-S 18-45mm f/4.5-6.3 IS STM's f/4.5 — more light and shallower depth-of-field.
| Product | ||
|---|---|---|
| Optical Design | ||
| Focal Length | 18-45mm | 30mm |
| Lens Type | Zoom | Prime |
| Optical Elements | 11 | 9 |
| Optical Groups | 9 | 6 |
| Aperture & Iris | ||
| Maximum Aperture | f/4.5 | f/1.4 |
| Minimum Aperture | f/22 | f/16 |
| Aperture Blades | 7 | 9 |
| Rounded Aperture | Yes | Yes |
| Coverage & Angle | ||
| Format Coverage | APS-C | APS-C |
| Lens Mount | Canon RF | Canon RF |
| Angle of View | 76° – 35° | 51° |
| 35mm Equivalent | 29-72mm | 48-48mm |
| Focus | ||
| Autofocus | Yes | Yes |
| Focus Motor | STM | HLA |
| Focus Limiter | No | No |
| AF/MF Switch | No | Yes |
| Min Focus Distance | 25 cm | 30 cm |
| Max Magnification | 0.29x | 0.1x |
| Stabilization & Video | ||
| Optical Stabilization | Yes | No |
| Aperture Ring | No | Yes |
| Declickable Aperture | No | Yes |
| Parfocal | No | No |
| Internal Zoom | Yes | No |
| General | ||
| Price (MSRP) | $299 | $349 |
| Filter Size | 49mm | 52mm |
| Diameter | 68.1mm | 64.8mm |
| Length | 44.8mm | 51.5mm |
| Weight | 149g (5.3 oz) | 265g (9.3 oz) |
| Weather Sealed | No | No |
| Tripod Collar | No | No |
