Review: The Canon 11-24mm f/4L is Pricey and Heavy but Unmatched Optically

Canon seems to be playing the numbers game against its arch-rival Nikon. Its new 50MP EOS 5DS and R-variant allowed Canon to leapfrog past Nikon’s D810’s 36MP in resolution. And with this new EF 11-24mm f/4L USM, Canon users can sneer at Nikon’s 14-24mm f/2.8G with “only” 14mm focal length.

But one shouldn’t forget that Nikon photographers have been enjoying 36MP for the past 3 years, and shooting gorgeous 14mm wide-angle images for more than 8 years. Canon is just catching up, but will this ultra wide-angle zoom lens be good enough to justify its retail price of $2,999?

Optical prowess and engineering

The Canon EF 11-24mm f/4L USM officially holds the title of the widest rectilinear full-frame SLR lens with its 126º05’ diagonal widest angle of view. And there’s no mistaking the lens for anything less than an extreme wide-angle lens given its huge and gorgeous 108mm bulbous front element.

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With any rectilinear wide-angle lens, the foremost concern of any photographer is the control of distortion. Bending light rays at extreme angles to accommodate the wide angles of view requires very complex optical construction, and it is common to spot visible barrel or pincushion distortion in such ultra wide-angle lenses. Canon promises the “new optical array provides straight lines with minimal curve throughout the zoom range”, with four aspherical lens elements to help minimize distortion from the center of the image to the periphery.

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When the first images of the lens appeared online, photographers had concerns about flare. With 16 elements in 11 groups and a huge front element, the Canon EF 11-24mm f/4L USM looks like it’ll have more flare than J J Abram’s movies. However, Canon is confident its proprietary Sub-Wavelength Structure Coating (SWC) and Air Sphere Coating (ASC) will effectively combat incidental light rays and direct light rays respectively.

But it’s not f/2.8!

Yes, it’s f/4 and not f/2.8. But I wouldn’t want it to be f/2.8, and I suspect neither would you after you’ve handled and used the Canon EF 11-24mm f/4L USM. Weighing in at 1180g or 2.6lb, it is already quite a hefty lens that is quite literally a handful to use. In contrast, despite being a stop brighter at f/2.8, the Nikon 14-24mm weighs in 10% lighter. Squeezing in the additional 3mm at the wide-end, along with all the optical sorcery required to keep distortion and flare at bay, has hurt the weight and size of the Canon. A lens that heavy, bulky and pricey at f/4 would probably be impossible to manufacture at f/2.8 maximum aperture – at least not without breaking the bank or your back, or both.

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Many photographers will not find the occasion to shoot at 11mm, but architecture photographers and landscape photographers will. These are photographers who require precision in composition and framing, shoot mounted on a tripod and would appreciate a lighter lens on long treks. After shooting the mandatory test shots for distortion control, I took the EF 11-24mm f/4L USM for some general photography. I can’t honestly say I find the 11-15mm focal range to be easy in general photography; in fact, I was forcing myself to be shooting at the ultra-wide focal length range just for this review. The EF 16-35mm L II would be a much better lens for general photography, and at f/2.8.

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Build quality

The construction of the Canon EF 11-24mm f/4L USM is polycarbonate, seen in many of the newer EF L lenses (except the super telephotos). It has a nice splattered matte high quality finish that looks like it’ll endure a good amount of abuse. The front petal hood is built in, made from the same polycarbonate as the body. The lens feels well built overall, with nicely dampened focusing and zoom rings, but it’s not something you’d write home about.

Optical performance

For many Canon photographers who’ve not used the Sigma 12-24mm, the widest full-frame rectilinear Canon zoom lens was the 16-35mm. Now that the Canon EF 11-24mm f/4L USM expanded the field of view to 11mm, is there a lot of difference between the 5mm of extra wideness?

The answer is – plenty. 5mm does not sound like a lot in the longer focal range, but in the ultra-wide angle range, every millimetre of focal length counts for a lot. Here I’ve photographed the scene with the different focal lengths – from 24mm all the way to 11mm, and you can see the large differences between 11mm to 16mm.

aFocal length 24mm

aFocal length 20mm

aFocal length 18mm

aFocal length 16mm

Focal length 14mm

Focal length 11mm

And in terms of geometric distortion, my personal take is that the Canon EF 11-24mm f/4L USM is exceptionally well corrected compared to the Sigma 12-24mm at all comparable focal lengths. The Canon optical engineers spared no effort in creating an ultra wide-angle lens with minimal distortion, and their persistence is reflected in the exceptional images rendered by the lens.

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There is very little visible geometric distortion in the images from 11mm to 24mm, and these sample images above have not undergone any distortion correction – post-production or otherwise. This is an incredible performance for any wide-angle optics, not to mention an ultra wide-angle lens.

aVignette and sharpness test 1 f4

aVignette and sharpness test 2 f5.6

aVignette and sharpness test 3 f8

aVignette and sharpness test 4 f11

aVignette and sharpness test 5 f16

aVignette and sharpness test 6 f22

The sweet spot of the Canon EF 11-24mm f/4L USM lies around f/8. Wide open at f/4, there’s visible vignetting all around, which doesn’t go away until f/5.6. Once you reach the optimum aperture of f/8 to f/11, the lens is extremely sharp and capable of resolving the finest details, possibly designed with the coming 50MP Canon DLSRs in mind. At f/16 to f/22 though, you can see diffraction creeping in to rob the image of critical sharpness from the test images.

So optically the lens fares very well, but does it flare as well?

Amazingly, it is not that easy to induce flare with the Canon EF 11-24mm f/4L USM. I directed the lens straight into the sun, hoping to see some gigantic solar flare all over the image, and all I got was a very well controlled hot-spot which was the sun, with the peripheral retaining excellent contrast and colours. Opened up or stopped down, the lens demonstrated the same great flare control, which was amazing considering the globe-like front element.

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The instances in which I managed to capture some flare happened when strong sunlight struck the side of the lens at sharp incident angles. Even then, the flare was very localized and controlled. As you can see from the images, Canon’s Sub-Wavelength Structure Coating (SWC) and Air Sphere Coating (ASC) worked exceptionally well to control flare in this complex piece of optical engineering.

The specialized lens

If the $3,000 price tag hasn’t positioned the Canon EF 11-24mm f/4L USM as a specialty lens, the insanely wide focal length should provide some hint. After using the lens for an hour or so at 11mm, the 24mm setting felt like 35mm. It takes a while to get used to the ultra-wide range.

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This is not an easy lens to use for general photography, at least in my experience. One good tip to creating great wide-angle images is to watch out for foreground interest. Wide-angle lenses create a lot of foreground space, and the wider you go the more foreground space you create. In the case of the Canon EF 11-24mm f/4L USM, there’s enough space at 11mm to fit an Imperial Destroyer in the foreground. Keeping the foreground occupied with interesting and relevant subject is quite a challenge, not to mention keeping your subject a reasonable size at 11mm.

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Retrofocus ultra-wide focal lengths such as 11mm also create distortions that “pull” objects at the corners towards the centre, which are not geometric distortions that lens designers can correct for. For any kind of photography, this is a problem that photographers have to deal with whenever ultra wide-angles are used. The wider the lens, the more obvious this effect becomes. Heads and faces near the edges become elongated and stretched, so beware of this optical effect when shooting group portraits with such lenses.

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Do watch out for exposure accuracy when using ultra-wide angle lenses, as it is easy to fool the exposure meter into underexposure when a large expense of sky is included in the ultra wide-angle scene. Set your exposure manually or do selective meter reading if your meter is fooled by the huge expense of bright skies or reflective surfaces.

Canon or Sigma?

While some take exception to the exceptional price of the Canon over the Sigma 12-24mm, the minimal distortion of the Canon will go some way in convincing some photographers to pony up the extra dough. The time saved in not having to correct the geometric distortions of the Sigma is invaluable to many photographers, and they will find the extra value of the Canon worth paying for.

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In addition, the Canon delivers sharper results at comparable aperture settings and vignettes less (possibly due to the larger front element), and it is extremely flare resistant as well. All these attributes make the Canon a very attractive lens to photographers who make a living with ultra-wide angle lenses, and the Canon is probably a worthwhile investment.

Sigma 1224

For other photographers though, the Sigma will do a decent enough job of satisfying the need for an ultra wide-angle. A third of what the Canon costs, the Sigma covers pretty much of what the EF 11-24mm does, albeit not as well optically. One thing the Sigma trumps the Canon though, is the ability to use filters. With its monstrous front element, it is not currently possible to fit any filters in front of the Canon EF 11-24mm f/4L USM (the lens allows for rear gel filters though). So if you are intending to fit a polarizer or gradated filter on the Canon, you are out of luck because it only accepts slot-in gel filters at the back. Until filter manufacturers figure out a way to accommodate the new Canon ultra-wide, the Sigma is still the only choice if you need to use such filters.

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Conclusion

The Canon EF 11-24mm f/4L USM is heavy and bulky. It is also thrice as costly as the Sigma, which offers slightly narrower focal length and less brightness. However, if image quality (in terms of distortion and sharpness) and flare control is important to you, then there is really no contest between the two lenses. The Canon EF 11-24mm f/4L USM is an outstanding performer in the rarefied group of ultra-wide SLR zoom lenses, by itself or compared to other super wide zooms.

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It is not for every photographer though, given its ultra wide focal length. General photography has limited use for ultra wide focal lengths, given the potential for distortion in the corners and requirement for careful composition to include foreground interest. And viewers tire easily of converging perspective shots, no matter how dynamic they are, if you shoot more than a handful of them.

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But for landscape and architectural photographers, the Canon EF 11-24mm f/4L USM is a lens they have been waiting for. Sharp, contrasty and virtually distortion-free, the Canon lens stretches your photography potential as much as it stretches your wallet. For the other Canon photographers who need an ultra-wide occasionally, there is always the option of the Sigma 12-24mm f/4.5-5.6 DG II HSM.


P.S. For high resolution sample photos from the Canon EF 11-24mm f/4L USM, check out the photos in this Flickr gallery.


About the author: Nelson Tan is a photographer based in Singapore. You can contact him through his Facebook, blog, and his photo gallery.

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