The Canon RF 45mm F1.2 STM is a fast prime lens that expands the STM lineup already available in the RF system (24, 28, 35, 50 and 85mm), standing out thanks to its f/1.2 maximum aperture instead of the more common f/1.8, f/2 or f/2.8. Canon positions this lens as a creative alternative, aimed at photographers who want a more expressive look and stronger subject separation without stepping into the size, weight and cost of professional L-series optics.

The 45mm focal length offers a natural perspective, slightly wider than a traditional 50mm, making it well suited for environmental portraits, street photography, light reportage and everyday shooting. On APS-C EOS R cameras, it delivers an equivalent field of view of approximately 72mm, making it a solid option for tighter portrait work as well.

From a design standpoint, Canon chose a relatively simple optical construction (9 elements in 7 groups), accepting a number of deliberate compromises. Early samples show noticeable vignetting at wide apertures, and distortion correction is clearly intended to be handled through in-camera and software corrections. Canon itself describes this lens as one focused on “character” and rendering style, rather than on achieving perfect chart-based performance.

Autofocus, size and real-world use

Autofocus is driven by a gear-driven STM motor, a choice consistent with the lens’ philosophy: smoothness and quiet operation take priority over outright speed. Given the amount of glass involved, the RF 45mm F1.2 STM is not the fastest-focusing prime in Canon’s lineup, but in practice it performs similarly to lenses such as the RF 85mm F2 STM.

In typical shooting scenarios – portraits, street photography, lifestyle work – autofocus performance is more than adequate, while continuous AF on static subjects can reveal slight vibrations or faint noise, especially at close focusing distances. For video work, focus transitions remain smooth and controlled, in line with expectations for an STM lens.

One of the lens’ strongest points is its portability: measuring approximately 78 × 75 mm, weighing just 346 g, and accepting 67 mm filters, the RF 45mm F1.2 STM is impressively compact for an f/1.2 optic. Minimum focusing distance is 45 cm, with a maximum magnification of 0.13×, suitable for close details and environmental close-ups.

These characteristics make the lens especially appealing to photographers and creators looking for a fast, everyday prime without the bulk and weight of professional-grade optics.

Price and market positioning

The most distinctive aspect of the Canon RF 45mm F1.2 STM is its pricing strategy. While it is not part of the L-series, Canon positions it well above traditional STM lenses, justifying the price through its f/1.2 aperture and its focus on creative rendering rather than technical perfection.

This lens is clearly aimed at advanced enthusiasts and creative photographers who want to explore extremely shallow depth of field and a more organic image character, rather than those prioritizing maximum sharpness at wide apertures.

Availability: Canon RF 45mm F1.2 STM is expected to be available from December 2025.