Canon has taken the wraps off its smallest RF-mount lens to date, with the Canon RF 28mm F2.8 STM being an ultra-compact ‘pancake’ design that’s less than 25mm long and weighs just 120g. This means that it’s slimmer than the likes of the RF 50mm F1.8 STM and RF 16mm F2.8 STM, which were the smallest RF lenses until now.

Canon RF 28mm F2.8 STM on Canon EOS R100

Canon RF 28mm F2.8 STM on Canon EOS R100. Credit: Andy Westlake

Despite its diminutive dimensions, it’s fully compatible with the firm’s full-frame mirrorless cameras. But it’s perhaps even better suited to compact APS-C models, on which it will give an angle of view equivalent to 45mm on full-frame.

The lens achieves its diminutive dimensions by using an innovative design. It employs 8 elements in 6 groups, with a tiny front element but three dramatically larger lenses towards the back. Not only do these employ highly aspherical profiles, they’re also cut to a rectangular shape to allow them to fit inside the mount section.

Canon RF 28mm F2.8 STM rear view

Elements towards the rear of the lens are cut to a rectangular shape. Credit: Andy Westlake

One welcome addition is a new 3-way switch for the manual focus ring, with AF, MF and Control positions (the latter allows control over settings such as aperture or ISO). Other key features include a minimum focus distance of 23cm, giving 0.17x magnification, and compatibility with the focus breathing correction function on recent Canon cameras. The lens employs a 7-blade aperture, accepts 55mm filters, and will cost £349.99.

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