In this cityscape you can see how well the updated 16-35mm F2.8L handles coma and how well it can perform when shot wide open. Seattle, WA

Photo by Chris Williams

Canon 5D Mk IV, 16mm, F2.8, 1.6 sec, ISO 100

The updated Canon 16-35mm F2.8L III USM offers a pretty incredible performance upgrade from its predecessor. All of the major issues that plagued the previous iteration of the lens including coma and lateral CA, and particularly sharpness both wide open and stopped down, have been addressed. Lateral chromatic aberration was a major issue in the previous version of this lens, to the extent that it reduced sharpness. The new lens dramatically corrects these sharpness and CA issues, especially at 16mm.

The only area where the lens falls short is at the long end of the focal range, where corner sharpness issues require you stop the lens down to F8 for optimal performance. It is still much improved over the prior version, but we would have liked to have seen it perform well across the entire focal range given the increased price.

Here's an example of the stunning sunstars that are possible with this lens. Seattle, WA

Photo by Chris Williams

Canon 5D Mk IV, 16mm, F10, 1/125 sec, ISO 100

At 16mm the lens seems to perform the best when shot wide open at F2.8, to the point that you notice the effects of diffraction as early as F5.6. The sharpness and overall image quality is downright impressive at the wide end and the lens offers exceptional overall performance that surpasses the previous iteration in nearly every category.

If you're considering a zoom lens for astrophotography as opposed to a fast prime, the lens handles coma very well and offers incredible sharpness and performance wide open. The differences between the updated version of the lens and its predecessor in terms of coma are really night and day. This means that image quality and detail when shooting the night sky or dimly illuminated scenes will really only be impacted by the performance of the sensor in the camera and not by the performance of the lens, especially at 16mm.

The Ring-type Ultrasonic autofocus system is a bit faster in the updated version of the lens than its predecessor, albeit the differences are fairly negligible, with both lenses performing equally well.

Final Word

This lens is dangerously sharp at the wide end. Seattle, WA

Photo by Chris Williams

Canon 5D Mk IV, 16mm, F3.5, 1/100 sec, ISO 100

With all of this in mind the question really is: to upgrade or not to upgrade? I think that the lens' performance really speaks for itself. Although the sharpness falls off a bit at focal lengths beyond 24mm, it's largely recoverable by stopping down. The real story here is the lens' exceptional performance wide open, and the fact that it outperforms its predecessor in literally every category, in a big way. I've owned the Canon 16-35mm F2.8L II for a number of years and the performance wide open has always been a major point of frustration for me; especially in terms of coma, CA and corner sharpness. Worse, things didn't always improve much upon stopping down. The new lens addresses all of these points and corrects the major issues seen in its predecessor. It's really quite impressive.

The sunstar is one area in particular where I was most concerned as it's one of the most distinguishable and sought-after aspects of the previous iteration of the lens. Luckily, the sunstar in the updated lens is really quite nice and it is fairly distinguishable from those produced by other lenses on the market. It also retained many of the characteristics that made the prior iteration so famous, such as minimal flare and defined clean rays, while bringing improvements like symmetry and 4 additional rays.

The updated version of the lens ticked all of the boxes and even exceeded my expectations at 16mm. All told, the upgrades are worth the price increase and if I were given the opportunity to upgrade, I would in a heartbeat. In fact, this lens will probably be the envy of competing systems.

Canon EF 16-35mm F2.8L III USM
Category: Wideangle Lens
Optical Quality
Build Quality
Ergonomics and Handling
The updated Canon 16-35mm F2.8L III offers some incredible performance wide open at 16mm. It's one of the sharpest wide angle zoom lens options on the market. Many of the issues such as coma, chromatic aberration and corner sharpness have all been addressed in this update and the results are impressive. The lens does suffer a bit in terms of sharpness at focal lengths beyond 24mm, but many of those issues can be resolved by stopping the lens down. If you're in the market to upgrade your 16-35mm F2.8L II or if you're looking for a fast wide-angle zoom, then this lens is an excellent option.
Good for
Low-light event photography, landscape, cityscape and architectural photography and those looking for a wide-angle zoom option for astrophotography.
Not so good for
Portrait, studio work or macro photography.
Overall score

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