Review of the Canon EOS RF 16mm F2.8 STM

Canon surprised everyone when they released the Canon RF 16mm F2.8. Most people thought there was no way this could be a full frame lens. However, it was, albeit with some caveats.

If you have been following us for very long, you would have noticed that I have been calling out to my dismay the multitude of patent applications of lenses that Canon files with image circle stretching - which means the image circle projected by the lens aren't quite big enough for full frame. But this trick works with mirrorless cameras, since with mirrorless, everything is electronic including our view through the viewfinder. Thus the manufacturers can on the fly manipulate the image and stretch that image circle to be larger and fill the frame. Of course, this has a drawback of resolution. But to be fair, this allows manufacturers to produce cheaper and smaller lenses.

The RF 16mm F2.8 falls in this category - but let's be fair, it's a $300 F2.8 16mm lens. The core features of the RF 16mm include;

RF-Mount Lens/Full-Frame Format
Aperture Range: f/2.8 to f/22
One Aspherical Element
Super Spectra Coating
STM Stepping AF Motor
Customizable Control Ring
Rounded 7-Blade Diaphragm

OpticalLimits who are one of my favorite lens review sites of all time took a look at the RF 16mm F2.8 and concluded basically the same;

The Canon RF 16mm f/2.8 STM is a lens with many facets. It comes down to where you come from and what you want. For instance, if you own an EOS R3 or R6, it's a decent ultra-wide prime lens - because, at 20 megapixels, even a Coke bottle is sharp enough. Well, almost. While on an EOS R5 and 45 megapixels, you don't really want to look at the image corners. It is, of course, also worth noting that this is the cheapest, fast ultra-wide prime ever released from a genuine manufacturer. Even when ignoring all quality concerns, it's dirt cheap for what it is. If you can't afford the real thing, having a 16mm ultra-wide lens is better than having none at all.

They gave it a damning review in terms of optical quality with 1.5 to 2.5 stars depending on what resolution of sensor you have in your camera, but also turned around and gave it an enthusiastic 5 out of 5 stars for price per performance.

You can read the full review here