17mm-Canon Lens War Shootout

Welcome to the first shootout comparison in the Canon 16-35mm f/2.8L II and the Canon 17-40mm f/4L to see which lens is the visually better lens at the 17mm focal range.

Now of course, the 16-35 and 17-40 are not portrait lenses, especially when at 17mm. But, throughout the entire range, we needed to shoot the same image so that we can properly compare each lens and image to one another.

For those that are new to the SLR Lounge Canon Lens Wars series, be sure to check out the Canon Lens Wars Intro video to learn more about the series and our testing methodology. Additionally, you can visit the Canon Lens Wars homepage to view all the other videos on each focal length.

Watch the 17mm Canon Lens Wars Video

Equipment Used

Canon Lenses Tested

Image Quality at Wide Open Apertures

Let’s start from the top with their visible aesthetic qualities at their respective Wide Open Aperture (WOA). Once again, this is a visual test of differences, not a technical test. So, we are trying to distinguish differences in appearance while viewing images full screen on a Dell U2713HM 27″ IPS monitor.

Canon 16-35mm f/2.8L II at f/2.8
Canon 16-35mm f/2.8L II at f/2.8
Canon 17-40mm f4L at f/4
Canon 17-40mm f/4L at f/4

So at a Wide Open Aperture of f/2.8, I immediately notice that the Canon 16-35mm f/2.8L II is actually rendering a decent amount of bokeh compared to the Canon 17-40mm f/4L. The 16-35mm’s bokeh is most noticeable in the area surrounding our model.

17mm-WOA-f2.8 Canon 16-35mmf2.8-17-40mmf4

Its not a ton of bokeh, but still it is impressive given that it is at 17mm. However, the model is slightly less sharp in the 16-35mm shot when compared to the 17-40mm at their respective WOA. It’s not by much, but there is a slight difference as you can see in the image below.


Interestingly, while the 17-40 has slightly better center frame sharpness, the 16-35 is still visually sharper towards of the edges of the frame even when at f/2.8 which you can see in the image below.


Color and contrast appear to be pretty equal with the Canon 16-35mm f/2.8L II having the slight edge.

Image Quality at Widest Common Aperture

Canon 16-35mm f/2.8L II at f/4
Canon 16-35mm f/2.8L II at f/4
Canon 17-40mm f4L at f/4
Canon 17-40mm f4L at f/4

Now, when we jump up to both lenses’ WCA or Widest Common Aperture at f/4, the Canon 16-35mm f/2.8L II steps ahead visually. Here, the 16-35 still displays far more bokeh than the 17-40 which really appears to have none. We can see the differences when looking at the area directly to the side of our model.


Center image detail and sharpness in the 16-35mm has again stepped beyond the 17-40mm which can be verified when zoomed into the dress area on our model below.


In addition, edge detail is clearly visibly sharper on the 16-35 as well as can be seen below.


Since we have stepped beyond f/2.8, the 16-35’s lens vignetting is significantly reduced at f/4 while the 17-40 still has quite a bit. Also, color and contrast are rendering a little better on the 16-35 as well at f/4.


Visually, the Canon 16-35mm f/2.8L II creates more bokeh and a different look that holds up all the way through around f/8 where they both equalize in terms of bokeh. However, throughout all apertures the 16-35 remains sharper from center-to-edge compared to the Canon 17-40mm f/4L which is extremely soft around its edges. It also retains slightly better contrast and color as well throughout all of the apertures, though it is most noticeable with both lenses around f/4.

Lens Distortion

Distortion was also quite similar between both lenses at the 17mm focal length. Both lenses had a very similar a mount of barrel distortion, and both showed roughly the same amount of perspective distortion caused by the cameras positioning being so close to the subject matter. Our model looks slightly more distorted on the 16-35, but most likely that was simply caused by the slight change in framing on the 16-35.

Canon 16-35mm f/2.8L II at f/2.8
Canon 16-35mm f/2.8L II at f/2.8

Low Light Consideration

When it comes to low light situations, the 16-35mm is going to give you a full extra stop of light performance, or double the light, than compared to the 17-40. In addition, at f/2.8 the overall center-to-edge sharpness of the 16-35 is far better than the 17-40mm, making its wide open setting a bit more functional.


So to recap, when put to a real world visual test, the Canon 16-35mm f/2.8L II is simply a better lens in every regard. It renders a decent amount of bokeh for an extreme wide angle lens even when at the same aperture as the 17-40. The 16-35 also has better color and contrast, better center-to-edge sharpness and an additional stop of low light and bokeh performance as well.

But, the Canon 17-40mm f/4L has a list price of around $840 while the 16-35 is priced at $1699.

So if you are a hobbyist or if you are on budget AND you are primarily shooting landscapes and nature where you are working around f/8 to f/11, you may decide that at double the price, the 16-35 doesn’t provide a large enough difference to make the additional cost worthwhile. Their focal lengths are similar enough, the overall contrast and color coming from both is also quite similar as well. In that situation, it may make sense to save the money and go with the Canon 17-40mm f/4L.

Personally, since I generally am not shooting at wide apertures on my wide angle lenses, the extra stop of low light performance isn’t a good enough reason to justify the additional cost of the 16-35. But professionally, there is a strong reason to buy the 16-35 over the 17-40 and that is simply the superior center to edge sharpness. The 16-35 does a far better job of resolving detail from the center to the edge of the frame at every aperture. While most differences in lens sharpness can only be seen when doing side by side close up comparisons, this difference is clearly visible without zooming in or even doing a side by side comparison. So much so, that for professional use I would skip over the 17-40 if possible. It simply doesn’t have the center to edge sharpness that we need in our images, particularly at the apertures that I frequently use. So, I would say to save up and spend the extra money on the Canon 16-35mm f/2.8L II as it produces far noticeably better image quality than the 17-40.


I hope you enjoyed this 17mm focal range installment in the SLR Lounge Canon Lens Wars series. Be sure to check out the rest of the Canon Lens Wars Series.