With a maximum diameter of just 69.2mm and at 40.1mm in length, the Canon RF 16mm F2.8 STM seems tiny. You could easily think that its an EF-M mount lens and designed for an APS-C format camera like the Canon EOS M5 Mark II. Incidentally, if the RF 16mm F2.8 STM is used on a Canon R-series camera in APS-C crop mode, it produces a framing equivalent to a 25.6mm lens on full-frame.
Being small, it also takes a dinky 43mm filter, which is great news as smaller filters cost less.
As a result of its small size, the RF 16mm F2.8 STM only has one control ring. This can be swapped between being used for manual focusing or to adjust aspects such as the aperture, sensitivity (ISO) or exposure compensation with a flick of the switch on its barrel.
It’s not the most robust-feeling lens, but at 165g, RF 16mm F2.8 STM is perfect when you want to travel light. It’s also very discreet which could make it a nice lens for wide-angle street photography.