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

The Canon 24-70mm f/2.8L II is the latest fast normal zoom to fill the bags of professional photographers, offering incredible sharpness and surprisingly few optical compromises for a zoom lens. But while it was designed for the rigors of professional use, this lens is also a favorite of enthusiasts who want a portable alternative to a bag full of prime lenses.

Is it overkill? Maybe, but for hobbyist Canon shooters who just want the best zoom available for their system, the Canon 24-70mm f/2.8L II is as good as it gets. Just about the only thing we can fault this lens for is its lack of image stabilization, something Canon has brought to both the f/4 version of this lens and the EF-S 17-55mm f/2.8

Who's It For?

The Canon EF 24-70mm f/2.8L II USM is perfect for anyone who needs a lens that will be effective in most everyday shooting situations, including dim lighting, and who needs to be ready to capture just about anything at the drop of a hat. When used on a full-frame DSLR like the Canon EOS 6D or 5D Mark III, the focal range gets you wide, normal, and short telephoto shots without having to change lenses. Better still, the fixed aperture won’t change if you need to go from wide to tele, or vice versa.

That combination of features makes it ideal for photojournalists who'll want to capture both broad scenes and intimate details. It's also a surprisingly effective portrait lens in a pinch; the 70mm end of the zoom range, paired with the bright f/2.8 maximum aperture, can effectively blur away backgrounds, bringing your subject's face into sharp relief. The fast aperture is also good for shooting sports, where this lens is a frequent companion to a telephoto zoom like Canon’s 70-200mm f/2.8L.

While the 24-70mm f/2.8L II will work on Canon's APS-C DSLRs, like the EOS 7D Mark II and entry-level Rebel models, we can't recommend it. The lens is large and heavy, which will unbalance lighter, non-professional bodies. The smaller sensor used in these cameras also crops the lens's image circle, making it behave more like a 39-112mm lens. Without the wide-angle reach, the lens becomes significantly less useful as a do-it-all option. Instead, we'd suggest the Canon EF-S 17-55mm f/2.8 IS USM, which is this lens's APS-C equivalent.

Look and Feel

Tech writers are fond of "war" metaphors. You’ve probably heard of the “megapixel war,” or companies that are crusading against this or that, or products that are "battle-tested." When you're talking about professional lenses, however, the metaphor becomes literal: These are products that were actually designed to go to war and come back with world-changing photographs.

The Canon 24-70mm f/2.8 is just such a lens. Like other Canon L-series lenses, it's built to survive in all conditions, from hurricanes to sand storms and more. It’s fully weather sealed, built from durable materials, and will survive more than a few spills here and there.

The fit and finish is also absolutely first class. Every switch flicks securely into place, the focus and zoom dials have just the right amount of resistance and throw, and the lens has a significant but not excessive heft (just under 2lbs) that makes it easy to stabilize when mounted on a similarly hefty pro camera body.

While it balances nicely with the larger grips found on cameras like the EOS-1D X and 5D Mark III, it can be a bit of a bear over a long day of shooting. The rise of mirrorless cameras is proof positive that today's consumers value smaller, lightweight gear, and this lens is way on the other end of the spectrum. That's fine for pros who require the 24-70 f/2.8L's top-flight image quality and versatility, but for regular folks it may be a bit too cumbersome.

{{ photo_gallery "tour" }}

Image Quality

The Canon 24-70mm f/2.8L II USM is widely regarded as one of the sharpest zooms around, and our testing bore that reputation out. It resolves fine detail remarkably well, with center sharpness routinely peaking well above what we'd consider excellent. The corners of the frame are roughly half as sharp at f/2.8 (still a good result), but as soon as you select a smaller aperture they improve, hitting their stride between f/4 and f/5.6.

Like most zoom lenses, the 24-70mm's performs differently at different points in the zoom range. In this case, 24mm delivers the strongest results, with sharpness slowly dropping away as you zoom out to 70mm. At that end, center sharpness is still excellent, but just barely. Of course, an excellent result is still an excellent result, and most users will be very happy with this lens at any focal length.

Chromatic aberration (color fringing) is an issue, however. At 24mm, there's moderate to severe fringing, especially at f/2.8. It begins to fade away as you zoom in, and by 70mm it's decidedly minimal. On the other hand, distortion is well controlled throughout—we recorded less than 1% barrel distortion at the wide end and slight pincushion distortion on the telephoto end.

In the real world, we found that the 24-70mm f/2.8L II does a fantastic job, delivering sharp shots with pleasing bokeh and few noticeable issues. Talking about bokeh, we were impressed with the roundness of out-of-focus points of light, but did notice some "onion ring" effect. It's a strong performance for a zoom, but we'd get a dedicated portrait lens if that's your thing.

Below you can see sample photos taken with the EF 24-70mm f/2.8L II USM mounted on a Canon EOS 5D Mark III. Click the link below each photo to download the full-resolution image.

{{ photo_gallery "sample-photo" }}

Conclusion

While photo enthusiasts suffer in the throes of GAS (gear acquisition syndrome)—endlessly buying hot new cameras and lenses, reselling them, and buying the next cool thing—professional photographers stick with what works. It’s a necessity: When you only have a split second to get the shot, you have to know your gear inside and out.

The Canon EF 24-70mm f/2.8L IS II is the kind of lens pros put their trust in. There are sharper lenses, lenses with better bokeh, and lenses with broader zoom ranges, but the 24-70mm f/2.8L offers a finely tuned mix of usability, flexibility, performance, size, price, and durability. That's why it's a mainstay in Canon’s esteemed lens lineup.

If you’re not a pro and just want a good, capable zoom lens, this is also a fine choice, but you may want to consider Canon's more affordable EF 24-70mm f/4L IS USM, which trades an extra stop of aperture for optical image stabilization and a more compact design. For most shooters, it'll do a similar job for about half the price.

But if you just want the best normal zoom Canon has to offer—one that you can grow with on the journey from amateur to pro—this is the lens to get. It's the one all other zooms in the Canon system are measured by.

When evaluating any lens, we focus on four key areas: sharpness, distortion, chromatic aberration, and bokeh. A perfect lens would render the finest details accurately, wouldn’t distort straight lines or produce ugly fringing around high-contrast subjects, and would create smooth out-of-focus areas.

The updated Canon EF 24-70mm f/2.8L II is a much sharper lens than most other zooms. It has some issues with chromatic aberration, and the bokeh (while generally excellent) has a few quirks, but they're all minor. There's a reason that this lens is so revered; it's spectacular, with a strong performance profile across the focal range.

Sharpness

A lens's sharpness is its ability to render the finest details in photographs. In testing a lens, we consider sharpness across the entire frame, from the center of your images out to the extreme corners, using an average that gives extra weight to center performance. We quantify sharpness using line widths per picture height (LW/PH) at a contrast of MTF50.

At 24mm, sharpness peaks at f/2.8, hitting roughly 2,450 lines right from the get go. From f/2.8 through f/8, center resolution stays above 2,000 lines, then falls off rather dramatically once the diffraction limit kicks in. Midway areas start at just 1,650 lines at f/2.8 before jumping above 2,000 lines from f/4 to f/8. The corners are (predictably) the softest part of the frame, starting at just 1,250 lines at f/2.8. They improve gradually as you stop down, peaking at f/8 and 1,825 lines.

You'll find a similar performance profile as you zoom in, though the corners don't improve quite so much. At the midpoint of the zoom range, the center and midway peaks are nearly identical, but the corners only get up to 1,600 lines at f/8 and f/11. The telephoto end sees almost no improvement in the corners, with resolution between 1,100 and 1,300 lines regardless of aperture. The center performance at 70mm is also slightly lower, though still excellent—a bit above 2,000 lines at f/2.8, hitting 2,200 lines by f/5.6.

Distortion

We penalize lenses for distortion when they bend or warp images, causing normally straight lines to curve. 

There are two primary types of distortion: When the center of the frame seems to bulge outward toward you, that’s barrel distortion. It's typically a result of the challenges inherent in designing wide-angle lenses. When the center of the image looks like it's being sucked in, that’s pincushion distortion. Pincushion is more common in telephoto lenses. A third, less common variety (mustache distortion) produces wavy lines.

Though the 24-70mm goes quite wide, it does a respectable job of keeping geometric distortion to a minimum. At 24mm, the usual barrel distortion is present, but it peaks at just 0.5%—hardly noticeable. As you zoom in, barrel turns to pincushion. At the midpoint it's still negligible, though by 70mm it jumps to around 1.8%. You'll see it in some straight-out-of-camera shots, but it's easy enough to correct in your photo editor of choice.

Chromatic Aberration

Chromatic aberration refers to the various types of “fringing” that can appear around high contrast subjects in photos—like leaves set against a bright sky. The fringing is usually either green, blue, or magenta and while it’s relatively easy to remove the offensive color with software, it can also degrade image sharpness.

The EF 24-70mm f/2.8L II is superb in many respects, but CA resistance isn't one of them. In our testing, aberrations were worst at f/2.8 and 24mm. There, CA peaked at around 0.14% on average—enough to be noticeable in high-contrast scenes. As we'd expect, it's worst in the corners, and likely plays a role in the weak corner resolution at f/2.8. As you zoom in, the CA slowly goes away. That's good news if you prefer portraits to architecture.

Bokeh

Bokeh refers to the quality of the out of focus areas in a photo. It's important for a lens to render your subject with sharp details, but it's just as important that the background not distract from the focus of your shot. 

While some lenses have bokeh that's prized for its unique characteristics, most simply aim to produce extremely smooth backgrounds. In particular, photographers prize lenses that can produce bokeh with circular highlights that are free of aspherical distortion (or “coma”).

The Canon EF 24-70mm f/2.8L II USM exhibits excellent bokeh in most situations, though it's best at 70mm. The lens renders out-of-focus areas smoothly, with very little aspherical distortion or coma wide open. Some high-frequency backgrounds can look a bit "busy" (seen in the sample below), but it's not a big deal.

The biggest issue we ran across in our test shots was that out of focus points of light, while rendered as large, circular orbs, also had some of the nastiest "onion ring" texturing that we've come across.

That's typical of lenses that feature aspherical elements, though some more recent designs from other manufacturers have taken steps to address the problem. It's not that noticeable in many shots, but if you sharpen your photo in post (even with local contrast adjustments like Lightroom's "Clarity" slider) you'll often amplify the rings along with all the other details.