The Canon RF 28-70mm f/2.8 IS STM lens is a compact, versatile zoom lens designed for Canon's full frame mirrorless cameras. With a constant f/2.8 aperture, it provides better performance in low light, greater subject separation, and a more professional feel than Canon's basic kit lenses. It strikes a balance between portability, performance, and cost, making it an interesting option for those looking to step up their photography game.
Coming to you from Christopher Frost, this comprehensive video examines the Canon RF 28-70mm f/2.8 IS STM lens, offering insights into its design and performance. It features a robust yet lightweight plastic construction with weather sealing around the rear mount, making it a good match for cameras like the Canon EOS R8. The lens measures just 3 x 3.6 inches when collapsed and weighs 1.1 pounds, making it surprisingly compact for a constant f/2.8 zoom. It features a broad zoom ring that operates smoothly without creeping and a front focus ring that can double as a customizable control ring. The STM autofocus motor is fast, silent, and accurate, excelling in both stills and video applications.
Key Specs
- Focal Length: 28-70mm
- Maximum Aperture: f/2.8
- Minimum Aperture: f/22
- Lens Mount: Canon RF
- Optical Design: 15 elements in 12 groups
- Diaphragm Blades: 9, rounded
- Minimum Focus Distance: 9.4 inches (24 cm)
- Maximum Magnification: 0.24x
- Angle of View: 75° to 34°
- Filter Size: 67mm
- Dimensions (ø x L): 3 x 3.6 inches (76.5 x 92.2 mm)
- Extended Length: 5.5 inches (138.9 mm)
- Weight: 1.1 pounds (495 g)
- Image Stabilization: Yes
The optical image stabilization system is particularly useful for handheld photography and videography in low light. Frost demonstrates how well the stabilization works, though he notes some minor jerkiness with aggressive movements. For image quality, the lens delivers impressive sharpness and contrast in the center at wider focal lengths and apertures. At 28mm and f/2.8, the center performance is razor-sharp, and even the corners hold up well. Zooming to 70mm, the center remains sharp, but the corners become softer, especially wide open. Chromatic aberration is visible at wider apertures but diminishes when stopped down.
Distortion and vignetting are noticeable without in-camera corrections. At 28mm, barrel distortion and strong vignetting are apparent, with pincushion distortion emerging at 70mm. Stopping down to f/5.6 improves vignetting, but post-processing corrections are necessary for distortion. The lens handles flare reasonably well, and coma is minimal even at f/2.8, making it a solid performer in challenging lighting.
The lens also excels at close-up photography with its 9.4-inch minimum focus distance. It delivers sharp results at 28mm, even wide open, while close-ups at 70mm benefit from stopping down to f/4. Autofocus is seamless, with the STM motor performing admirably across Canon’s full-frame mirrorless cameras.
While the $1,100 price point places this lens below Canon’s professional L series options, it’s still a significant investment. He also notes that for the same price, you could explore multiple high-quality prime lenses, which might offer superior image quality and creative flexibility. Check out the video above for the full rundown from Frost.
