Together with the new EOS R6 Mark III, Canon has announced the RF 45mm f/1.2 STM, a compact and relatively affordable fast prime lens for full-frame mirrorless cameras. The new model expands Canon’s STM lineup by offering an aperture previously reserved for its higher-end L-series lenses, positioning it as an option for users seeking shallow depth of field without the cost and size of professional glass.

The lens features a 45mm focal length that place it slightly wider than the traditional 50mm standard, weighs 346g, measures 75mm in length, and accepts 67mm filters, making it lightweight enough to suit handheld and gimbal use. Its optical structure includes nine elements in seven groups, incorporating one plastic-molded aspherical element that helps reduce size and weight while maintaining acceptable optical performance.

Distortion and vignetting are noticeable at wider apertures (as shown in the pictures below), an issue Canon addressed relying on in-camera corrections. The fast, nine-bladed f/1.2 maximum aperture enables strong background separation and low-light capability, though the Japanese company notes that the lens emphasizes “character” rather than technical perfection. Users should expect some softness and aberrations compared to the company’s more expensive options such as the RF 50mm f/1.2L USM.

Autofocus is driven by a gear-type STM motor, which helps keeping pricing accessible but makes it is slower and noisier than the USM motors found in L-series lenses. The lens supports full-time manual focus override, focus breathing correction compatibility, and features both a dedicated control ring and a separate focus ring. The minimum focusing distance is 45cm, allowing a maximum magnification of 0.13x.

Here are few sample pictures, courtesy of Canon: