Canon EF 24-70mm f/2.8L USM Lens

In Summary
Buy this lens if:
– You require a professional-quality standard zoom lens for use on DSLR cameras with ‘full-frame’ sensors.
– You want superior performance across a wide range of aperture settings with all focal lengths.
Don’t buy this lens if:
– You need macro capabilities.
Full Review
Although Canon’s EF 24-70mm f/2.8L USM has just been superseded by a second-generation model, we were offered the chance to review the original with the new EOS 5D Mark III camera and decided it would be worth the effort. This professional grade lens has been popular since its release in 2002 and, with the release of the significantly higher-priced Mark II model, represents good value for money.

Side view of the EF 24-70mm f/2.8L USM lens, shown without the lens hood. (Source: Canon.)
Although designed primarily for Canon DSLRs with 36 x 24mm sensors, it’s also usable throughout the Canon DSLR range. It’s not worth fitting on APS-C DSLRs where its field-of-view equates to 39-112mm, which isn’t particularly useful and is covered better by smaller, cheaper lenses. The size (83 x 123 mm) and weight (950 grams) of this lens are better suited to larger camera bodies.
The 24-70mm range on a ‘full frame’ camera extends from a moderate wide angle suitable for landscape photography through the ‘standard’ 50mm focal length that replicates normal human vision to a slightly longer focal length. Wedding photographers value this lens for its large maximum aperture, which enables good differential focusing with portrait shots, particularly in low light levels.
With a minimum focusing distance of 38 cm, this lens only reproduces at approximately 1/3 life size with 70mm so it can’t be seen as macro-capable. However, it can be used for close-ups, although not with tiny subjects.
The optical construction comprises 16 elements in 13 groups and includes one UD elements and two aspherical elements. As with most current Canon lenses, all the elements are made of lead-free glass. Eight iris blades close to a circular aperture. Filter size is 77 mm.
A ring-type USM autofocusing drive based on a front-focusing system provides very fast focusing. It’s virtually silent when the camera’s phase-detection AF system operates and usable with the contrast-based Live View mode.
Build and Ergonomics
Sealed against dust and moisture (although not totally waterproof), this lens can be used for shooting in challenging environments. Its build quality is outstanding, with absolutely no slackness and smoothly moving focusing and zoom rings.
There’s a durable metal mounting plate and the focus and zoom rings feel firm enough to provide very precise adjustments. The 25 mm wide focusing ring is located approximately 35 mm behind the front of the lens when it’s in the 70mm position.
It has an 18 mm wide ribbed rubber grip and rotates through 180 degrees. A distance scale is inset into the barrel just behind the focusing ring. In MF mode you can feel slight resistance at each end of the distance scale (infinity and 0.38 metres).
Left of the distance scale on the same section of the lens barrel is an AF/MF slider switch. Full-time manual focus over-ride is available in one-shot AF mode.
The 23 mm wide zoom ring is just in front of the mounting plate. It has a 17 mm wide ribbed grip band with much thicker ribbing than the focus ring. It turns through an arc covering roughly 40 degrees. Focal length settings engraved on the trailing edge of the ring line up against a white line just in front of the lens mount.
The zoom mechanism is the reverse of the normal system because the inner barrel extends towards the 24mm position. Although a lens hood was not provided with the review lens, the deep, petal-shaped hood that matches this lens attaches to the outer barrel, which means the front element remains inside the hood while zooming and the length of the lens doesn’t change.
The front element does not rotate during focusing or zooming, allowing use of angle-critical attachments like polarisers. But with the hood in place, they could be difficult to adjust at longer focal lengths.
Performance
Our shooting tests were carried out with the Canon EOS 5D Mark III body, which was a good match with the lens. Autofocusing was fast, quiet and accurate and the f/2.8 maximum aperture provided full scope for the high sensitivity of the camera’s AF point array.
Imatest showed the lens to be capable of matching the performance of the 5D III’s sensor with best performance around f/5.6 at the 35mm focal length. The graph below shows the results of our tests.

Lateral chromatic aberration was consistently negligible at all focal length and aperture settings. In the graph of our Imatest results below, the red line marks the boundary between ‘negligible’ and ‘low’ CA.

Vignetting was very well controlled and only just visible at the widest aperture settings. Stopping down only one f-stop made it disappear. Distortion was also very low for the lens’s focal length range, with only slight barrel distortion visible at 24mm and nothing significant thereafter.
Without the lens hood, the review lens was flare prone in backlit situations, particularly at wider angles of view. The 70mm focal length handled backlit subjects quite well. Bokeh was smooth and very attractive.
We will review the new EF 24-70mm f/2.8L II USM lens as soon as it becomes available.
SPECS
Picture angle: 74 degrees to 29 degrees
Minimum aperture: f/22
Lens construction: 16 elements in 13 groups
Lens mounts: Canon EF
Diaphragm Blades: 8
Focus drive: USM (ultrasonic motor)
Stabilisation: No
Minimum focus: 38 cm
Maximum magnification: 0.29x
Filter size: 77 mm
Dimensions (Diameter x L): 83.2 x 123.5 mm
Weight: 950 grams
TESTS
(based on JPEG files from the Canon EOS 5D Mark III)



SAMPLES

Vignetting at 24mm.

Vignetting at 35mm.

Vignetting at 70mm.

Rectilinear distortion at 24mm.

24mm focal length; ISO 100, 1/60 second at f/14.

28mm focal length; ISO 100, 1/100 second at f/14.

35mm focal length; ISO 100, 1/80 second at f/14.

50mm focal length; ISO 100, 1/200 second at f/14.

70mm focal length; ISO 100, 1/120 second at f/14.

Close-up at 0.39 m from the subject; ISO 100, 1/100 second at f/3.2.

Close-up at 0.39 m from the subject; ISO 1600, 1/120 second at f/22.

Flare at 24mm with strong backlighting and no lens hood; ISO 100, 1/50 second at f/14.

A shot taken from the same position with the lens at 70mm; ISO 100, 1/60 second at f/14.

40mm focal length, ISO 100, 1/500 second at f/11.

24mm focal length, ISO 100, 1/320 second at f/8.

70mm focal length, ISO 125, 1/60 second at f/6.3.

196: 43mm focal length, ISO 100, 1/400 second at f/7.1.

50mm focal length, ISO 400, 1/50 second at f/10.
Rating
RRP: AU$2049; US$1399
- Build: 9.0
- Handling: 8.8
- Image quality: 9.0
- Versatility: 8.5
- Overall: 8.5