Canon RF 16-28mm f/2.8 STM: Is the Distortion a Dealbreaker?

The Canon RF 16-28mm f/2.8 STM is one of the more interesting ultra-wide angle zoom lenses Canon has released in recent years, sitting at a price point that's hard to categorize. It's not cheap, but it's marketed as the budget option in Canon's lineup, which raises an obvious question: what exactly are you giving up?

Coming to you from Christopher Frost, this thorough video puts the Canon RF 16-28mm f/2.8 STM through its paces on a Canon EOS R5. Frost starts with build quality, and the short version is: plastic, but not embarrassingly so. At 445 g, it has some weight behind it, the mount is metal with weather-sealing, and the lens feels reasonably solid. The collapsible design does mean you have to extend it before shooting, and that initial snap when deploying it is, as Frost puts it, "slightly hard and unpleasant." Autofocus is silent and accurate with no issues there, and the 5.5 stops of image stabilization is genuinely useful, especially on bodies like the EOS R8 that lack in-body stabilization.

Sharpness in the center is strong at both 16mm and 28mm, even wide open at f/2.8. Corners are softer but still reasonable, and stopping down helps. What's harder to ignore is what happens when you pull a raw file. Frost shows the uncorrected distortion, and it's dramatic, heavy barrel distortion that forces the camera to crop and stretch the image just to produce a usable JPEG. Canon doesn't even give you the option to disable distortion correction in-camera, which tells you something about how dependent the optical formula is on that processing. That kind of correction has a real cost to corner resolution, and you can see it in the fine details on straight lines.

There's more in the video worth paying attention to. Frost looks at close-up performance, which is surprisingly capable down to around 20 cm, though you'll want to stop down to at least f/4 for contrast to firm up. He also tests the lens against bright light, where flare patterns are visible and contrast takes a moderate hit. Coma shows up in the corners at f/2.8 but clears up by f/5.6. Sun stars don't get interesting until around f/8, but by f/11 and beyond they're well defined. Bokeh, while hard to achieve at this focal range, looks smooth when you get close enough to your subject to throw a background out of focus.

At over $1,000, Frost is candid that he'd feel shortchanged paying full price, and he only recommends it if you can find a deal or the price drops. Check out the video above for the full rundown from Frost.