Sigma 15mm F1.4 DC Contemporary (Canon RF) vs Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF)
The bottom line
These cover different focal lengths — the Sigma 15mm F1.4 DC Contemporary (Canon RF) is 15mm, the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) is 18-50mm — so they're not really substitutes. Pick by the field of view you actually need: the Sigma 15mm F1.4 DC Contemporary (Canon RF) for wide-angle, the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) for standard.
Choose the Sigma 15mm F1.4 DC Contemporary (Canon RF) if…
- ✓You want more light and background blur — f/1.4 is faster than f/2.8, better for low light and subject separation.
- ✓You prefer a fast, compact single focal length — a 15mm prime over a zoom.
- ✓You value portability — at 220g (7.8 oz) it's lighter than the 290g (10.2 oz) alternative for travel and all-day carry.
Choose the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) if…
- ✓You need more reach — it goes to 50mm vs 15mm for distant subjects, wildlife and sport.
- ✓You want one-lens flexibility — a 18-50mm zoom covers what the fixed 15mm can't reframe.
- ✓You like close-focus work — 0.5x magnification vs 0.15x.
Where they differ
- ›Aperture: the Sigma 15mm F1.4 DC Contemporary (Canon RF) opens to f/1.4 vs the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF)'s f/2.8 — more light and shallower depth-of-field.
- ›Focal range: Sigma 15mm F1.4 DC Contemporary (Canon RF) is 15mm, Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) is 18-50mm — different framing and reach.
- ›Type: the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) is a zoom (flexible framing), the Sigma 15mm F1.4 DC Contemporary (Canon RF) a prime (one focal length, usually brighter and lighter).
- ›Close-up: the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) reaches 0.5x magnification vs 0.15x — more for close-up and macro work.
Frequently asked
Is the Sigma 15mm F1.4 DC Contemporary (Canon RF) or the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) better?
These cover different focal lengths — the Sigma 15mm F1.4 DC Contemporary (Canon RF) is 15mm, the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) is 18-50mm — so they're not really substitutes. Pick by the field of view you actually need: the Sigma 15mm F1.4 DC Contemporary (Canon RF) for wide-angle, the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) for standard.
Who should choose the Sigma 15mm F1.4 DC Contemporary (Canon RF)?
Choose the Sigma 15mm F1.4 DC Contemporary (Canon RF) if you want more light and background blur — f/1.4 is faster than f/2.8, better for low light and subject separation. Choose it if you prefer a fast, compact single focal length — a 15mm prime over a zoom. Choose it if you value portability — at 220g (7.8 oz) it's lighter than the 290g (10.2 oz) alternative for travel and all-day carry.
Who should choose the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF)?
Choose the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF) if you need more reach — it goes to 50mm vs 15mm for distant subjects, wildlife and sport. Choose it if you want one-lens flexibility — a 18-50mm zoom covers what the fixed 15mm can't reframe. Choose it if you like close-focus work — 0.5x magnification vs 0.15x.
What is the main difference between the Sigma 15mm F1.4 DC Contemporary (Canon RF) and the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF)?
Aperture: the Sigma 15mm F1.4 DC Contemporary (Canon RF) opens to f/1.4 vs the Sigma 18-50mm f/2.8 DC DN Contemporary (Canon RF)'s f/2.8 — more light and shallower depth-of-field.
| Product | ||
|---|---|---|
| Optical Design | ||
| Focal Length | 15mm | 18-50mm |
| Lens Type | Prime | Zoom |
| Optical Elements | 13 | 13 |
| Optical Groups | 11 | 10 |
| Aperture & Iris | ||
| Maximum Aperture | f/1.4 | f/2.8 |
| Minimum Aperture | f/16 | f/22 |
| Aperture Blades | 9 | 9 |
| Rounded Aperture | Yes | Yes |
| Coverage & Angle | ||
| Format Coverage | APS-C | APS-C |
| Lens Mount | Canon RF | Canon RF |
| Angle of View | 82.9° | 76° – 32° |
| 35mm Equivalent | 24-24mm | 29-80mm |
| Focus | ||
| Autofocus | Yes | Yes |
| Focus Motor | HLA | HLA |
| Focus Limiter | No | No |
| AF/MF Switch | Yes | Yes |
| Min Focus Distance | 18 cm | 13 cm |
| Max Magnification | 0.15x | 0.5x |
| Stabilization & Video | ||
| Optical Stabilization | No | No |
| Aperture Ring | Yes | Yes |
| Declickable Aperture | Yes | Yes |
| Parfocal | No | No |
| Internal Zoom | No | No |
| General | ||
| Price (MSRP) | $579 | $599 |
| Filter Size | 58mm | 52mm |
| Diameter | 64mm | 65.4mm |
| Length | 65mm | 76.9mm |
| Weight | 220g (7.8 oz) | 290g (10.2 oz) |
| Weather Sealed | Yes | Yes |
| Tripod Collar | No | No |
