Should I Get the Canon EF 16-35 f/2.8L II, EF 16-35mm f/4L IS or the EF 17-40mm f/4L Lens?

Those looking to add a Canon wide-angle zoom to their full-frame kits will likely be considering between the EF 16-35mm f/2.8L II USM, EF 16-35mm f/4L IS USM and EF 17-40mm f/4L USM lenses. At first glance, choosing between them may not seem easy.

The first thing to keep in mind when purchasing a wide-angle zoom lens is, "What is my intended use for this lens?" If the answer involves capturing action – like dancing at a wedding reception – then your decision is an easy one.

The Canon EF 16-35mm f/2.8L II USM lens' one-stop aperture advantage will allow you to use a shutter speed that's twice as fast as the other lenses at identical ISOs. Another way to look at it is that using an f/4 aperture to stop action would require doubling the ISO to achieve the same shutter speed obtained using an f/2.8 aperture. Considering that many wedding receptions are held in low light venues, using an f/2.8 aperture is the only way to freeze action and keep high ISO noise at bay without compromising the image quality with detail-robbing noise removal.

There are three drawbacks to the 16-35mm f/2.8L II, though – price, lack of image stabilization and an 82mm front filter thread. Of course, that last "drawback" may not be an issue if you have other lenses requiring 82mm filters (allowing for the ease of filter sharing), but the 77mm filter size is certainly more common and more likely already part of one's kit.

If shooting architecture, real estate, landscapes, cityscapes (or anything else with a "scapes" on the end), the other two wide-angle zoom options can be easily employed while minimizing the investment required to create such imagery.

If you don't require an f/2.8 maximum aperture and price is not a primary factor, get the Canon EF 16-35mm f/4L IS USM lens. Benefits of the 16-35 f/4L IS include a slightly wider focal length, 77mm filter threads, image stabilization and enhanced fluorine lens coatings for top notch image quality. The 16-35 f/4L IS will allow you to use shutter speeds 4-stops slower to capture sharp images of static subjects while hand-holding the camera, thereby making tripod use less of a necessity (great for backpacking adventures).

So why would you choose the EF 17-40mm f/4L USM over the other two options? The primary reason is price. However, rebate can affect the price comparison significantly. With the current instant rebates in place, the 17-40mm f/4L is only $250.00 less expensive than its 16-35 f/4L IS counterpart. Many will appreciate the 16-35 f/4L IS's benefits for the difference in price.

But again, if money is really tight, the 17-40mm f/4L is still an excellent option. One can easily give up image stabilization if using a tripod, and if shooting at f/8, you won't likely notice a sharpness difference between the two lenses at their widest focal lengths (though the 17-40L does exhibit more CA). Another benefit of the 17-40L is a slightly longer focal range, sacrificing 1mm on the wide end but gaining 5mm on the long end.

If size/weight is the ultimate deciding factor, the EF 17-40mm f/4L USM is the smallest and lightest with the 16-35mm lenses being very similar to one another in those regards. However, the EF 17-40 f/4L's lens hood is so big that it will take up significantly more space when affixed to the lens (reversed) compared to the EF 16-35 f/4L with its hood.

If image quality wide open is the ultimate deciding factor, the oldest lens of the bunch – the EF 17-40 f/4L USM – easily falls short of the other options. Take a look at the corner results of the 17-40 f/4L vs. 16-35 f/4L IS tested on the EOS 5Ds R at f/4 with the lenses set to their widest focal lengths. Of course a wide zoom lens isn't always used at its widest focal length and the IQ difference lessens at longer focal lengths, but... I feel that a wide-angle zooms are primarily purchased for their widest focal length capability, thereby making the widest focal length comparison most significant.

When comparing the EF 16-35mm f/2.8L II USM to the EF 16-35mm f/4L IS USM, differences in sharpness become much more nuanced when the lenses are compared at their widest common aperture of f/4 at 16mm. The 16-35 f/4L IS is definitely better in the corners, but not by a huge degree. When both lenses are compared wide open, the IQ chasm is greater as the f/2.8's stopped-down advantage disappears (the same is true for the 35mm results as well).

Of course, there are other factors that can impact image quality besides sharpness including distortion, flare and vignetting. Use the site's Comparison Tools to fully compare these lenses.

B&H carries the EF 16-35mm f/2.8L II USM, EF 16-35mm f/4L IS USM and EF 17-40mm f/4L IS USM lenses.