Conclusion

The Canon RF 28mm F2.8 STM is a cheap and cheerful wide-angle prime lens that delivers sharp images in the centre, fast and reliable auto-focusing, a usefully close shooting distance and surprisingly good build quality, all housed inside a tiny, super-lightweight pancake design.

It delivers excellent sharpness at the centre of the frame throughout most of its aperture range, even performing very well when shooting wide-open at f/2.8. It's a different story at the edges of the image, though, which are markedly softer, with the best results obtained from f/4-11.

When shooting JPEGs and video, there's some fairly mild vignetting which requires you to stop down by at least 2 f-stops to prevent it completely, but there's little evidence of chromatic aberrations.

Distortion is also well controlled for both JPEG and RAW files, as the camera body automatically applies digital corrections to the image - in fact, you can't turn this feature off when using this lens.

Shooting in the RAW format, however, is another matter entirely, because the lens relies so heavily on Canon's digital corrections which are either applied automatically in-camera or by the end user during post-processing.

These corrections aren't automatically applied to RAW files, which clearly exhibit large amounts of vignetting that some users may find objectionable.

This is by far the biggest compromise in producing such a small, light and cheap wide-angle lens - there really isn't too much else to complain about given the asking price.

The fly-by-wire manual focusing isn't particularly refined and it's also rather noisy in operation, there's no weather-proofing, and you don't get a case or even a hood included in the box, but we think they're pretty minor gripes for what is after all only a £$300 lens.

Overall, if you can buy into the amount of digital correction that Canon is automatically applying in-camera, then we can highly recommend the RF 28mm F2.8 STM as a classic prime for your wide-angle needs.

Ratings (out of 5)
Design	5
Features	4
Ease-of-use	4.5
Image quality	4
Value for money	4.5