Canon RF-S 18-45mm f/4.5-6.3 IS STM vs Canon RF20-50mm F4 L IS USM PZ
The bottom line
Similar coverage, different speed: the Canon RF20-50mm F4 L IS USM PZ opens to f/4 versus the Canon RF-S 18-45mm f/4.5-6.3 IS STM's f/4.5 — more light and shallower background blur. The Canon RF-S 18-45mm f/4.5-6.3 IS STM gives that up to stay lighter (149g (5.3 oz)) and cheaper ($299). It comes down to how much you value that extra brightness.
Choose the Canon RF-S 18-45mm f/4.5-6.3 IS STM if…
- ✓You're on a budget — $299 vs $1,399 leaves more for other gear.
- ✓You value portability — at 149g (5.3 oz) it's lighter than the 420g (14.8 oz) alternative for travel and all-day carry.
Choose the Canon RF20-50mm F4 L IS USM PZ if…
- ✓You work outdoors — it's weather-sealed against dust and moisture; the other isn't.
Where they differ
- ›Aperture: the Canon RF20-50mm F4 L IS USM PZ opens to f/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, Canon RF20-50mm F4 L IS USM PZ is 20-50mm — different framing and reach.
- ›Price: the Canon RF-S 18-45mm f/4.5-6.3 IS STM is $299, $1,100 under the Canon RF20-50mm F4 L IS USM PZ.
- ›Weight: the Canon RF-S 18-45mm f/4.5-6.3 IS STM is 149g (5.3 oz) vs 420g (14.8 oz) — you'll feel the difference handheld.
- ›Durability: the Canon RF20-50mm F4 L IS USM PZ is weather-sealed; the other isn't.
Frequently asked
Is the Canon RF-S 18-45mm f/4.5-6.3 IS STM or the Canon RF20-50mm F4 L IS USM PZ better?
Similar coverage, different speed: the Canon RF20-50mm F4 L IS USM PZ opens to f/4 versus the Canon RF-S 18-45mm f/4.5-6.3 IS STM's f/4.5 — more light and shallower background blur. The Canon RF-S 18-45mm f/4.5-6.3 IS STM gives that up to stay lighter (149g (5.3 oz)) and cheaper ($299). It comes down to how much you value that extra brightness.
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're on a budget — $299 vs $1,399 leaves more for other gear. Choose it if you value portability — at 149g (5.3 oz) it's lighter than the 420g (14.8 oz) alternative for travel and all-day carry.
Who should choose the Canon RF20-50mm F4 L IS USM PZ?
Choose the Canon RF20-50mm F4 L IS USM PZ if you work outdoors — it's weather-sealed against dust and moisture; the other isn't.
What is the main difference between the Canon RF-S 18-45mm f/4.5-6.3 IS STM and the Canon RF20-50mm F4 L IS USM PZ?
Aperture: the Canon RF20-50mm F4 L IS USM PZ opens to f/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 | 20-50mm |
| Lens Type | Zoom | Zoom |
| Optical Elements | 11 | 13 |
| Optical Groups | 9 | 11 |
| Aperture & Iris | ||
| Maximum Aperture | f/4.5 | f/4 |
| Minimum Aperture | f/22 | f/22 |
| Aperture Blades | 7 | 9 |
| Rounded Aperture | Yes | Yes |
| Coverage & Angle | ||
| Format Coverage | APS-C | Full-Frame |
| Lens Mount | Canon RF | Canon RF |
| Angle of View | 76° – 35° | 94° – 46° |
| 35mm Equivalent | 29-72mm | − |
| Focus | ||
| Autofocus | Yes | Yes |
| Focus Motor | STM | Nano USM |
| Focus Limiter | No | No |
| AF/MF Switch | No | Yes |
| Min Focus Distance | 25 cm | − |
| Max Magnification | 0.29x | − |
| Stabilization & Video | ||
| Optical Stabilization | Yes | Yes |
| Aperture Ring | No | No |
| Declickable Aperture | No | No |
| Parfocal | No | Yes |
| Internal Zoom | Yes | Yes |
| General | ||
| Price (MSRP) | $299 | $1,399 |
| Filter Size | 49mm | 67mm |
| Diameter | 68.1mm | − |
| Length | 44.8mm | − |
| Weight | 149g (5.3 oz) | 420g (14.8 oz) |
| Weather Sealed | No | Yes |
| Tripod Collar | No | No |
