RF28-70mm F2 L USM

RF28-70mm F2 L USM

Our endeavors to find the limits of optical design bear fruition here. This standard zoom lens boasts the world's first* maximum f/2 aperture, opening the way for yet-unknown expression in imaging. The large diameter and short back focus that characterize its RF mount enable an all-new flexible optical design and achieve high image quality on par with single focal-length lenses, across the range of zoom. Its effective arrangement of two ground aspherical elements, two glass-molded aspherical elements, and a super UD element delivers high resolution and high contrast from the center of the image to the periphery. In addition, two special coatings, SWC and ASC, suppress flaring and ghosting even in backlit situations. In wedding or portrait shooting, in landscape or astronomical photography, this lens surpasses conventional zoom lenses in expressiveness to make the dreams of photographers come true.

  • *Among interchangeable autofocus standard zoom lenses for 35mm full frame digital cameras. Based on Canon’s research.


  • RF28-70mm F2 L USM, Canon EOS R, 1/200sec., f/8, ISO100
  • RF28-70mm F2 L USM, Canon EOS R, 1/125sec., f/5.6, ISO100
  • RF28-70mm F2 L USM, Canon EOS R, 1/500sec., f/8, ISO100
  • RF28-70mm F2 L USM, Canon EOS R, 30sec., f/2, ISO3200


Angle of View
(horizontal, vertical, diagonal)
65°−29°/ 46°−19°30’/ 75°−34°
No. of Diaphragm Blades 9
Closest Focusing Distance 0.39m
Maximum Magnification 0.18x (at 70mm)
Water/dust Resistance Yes
Filter Size 95mm
Max. Diameter x Length Ø103.8 × 139.8mm
Weight Approx. 1,430g
Lens Cap E-95
Lens Hood EW-103
Lens Pouch/Case LP1424

  • Super UD element
  • UD element
  • Ground aspherical lens
  • GMo aspherical lens
  • SWC
  • ASC
  • Fluorine Coating

MTF Characteristics

Spatial frequency Maximum aperture
10 lines/mm
30 lines/mm
How to read
MTF characteristics

Spatial frequency Maximum aperture
10 lines/mm
30 lines/mm

The more the S and M curves are in line, the more natural the blurred image becomes.

Modulation Transfer Function, or MTF, is a method of evaluating lens performance using contrast reproduction ratio. When evaluating the electrical characteristics of audio equipment, one important measure of performance is frequency response. This indicates the fidelity of the reproduced sound with respect to the source sound as it passes through the microphone, recording and playback circuits, and finally the speakers. When the reproduction is accurate, the equipment is classified as “hi-fi,” or “high fidelity.”
In the same way, when a lens is viewed as a transmission system for optical signals, measuring the frequency response of the optical system reveals whether the optical signal is transmitted faithfully. For a lens, the equivalent of frequency is “spatial frequency,” which indicates how many patterns, or cycles, of changes in sinusoidal density are present in a 1 mm width. Accordingly, the unit of spatial frequency is lines per mm, as opposed to Hz in electrical systems.

The MTF characteristics shown on this website are 10 lines/mm and 30 lines/mm, where the horizontal axis indicates image height (the distance on a diagonal line from the center of the image, in mm) with the image center set to 0, and the vertical axis indicates contrast. The closer the 10-line/mm curve is to 1, the better the contrast and clarity of the lens; the closer the 30-line/mm curve is to 1, the better the resolving power and sharpness of the lens. Although a good balance between both of these is important for a lens to be sharp and clear, a lens is generally said to offer excellent image quality if the 10-line/mm curve is greater than 0.8, or satisfactory image quality if greater than 0.6.

Resolving power and contrast are both good

Contrast is good; resolving power is poor

Resolving power is good; contrast is poor