Canon’s New 45mm f/1.2 STM Redefines What Affordable Can Mean

Canon’s new 45mm f/1.2 STM lens is making waves for all the right reasons. A full frame lens with a maximum aperture of f/1.2 for under $500 is something no one expected, and it’s about to change how you think about affordable fast primes. 

Coming to you from Carl Yates with ProAV, this detailed video introduces the Canon 45mm f/1.2 STM lens, a surprisingly capable and compact piece of glass. Yates describes it as Canon’s first f/1.2 lens designed for everyday users, not just professionals. It weighs only 346 grams and measures 78 mm in diameter by 75 mm long, giving it a compact profile that balances well even on smaller bodies. The build feels solid enough, with a large, smooth focus ring and a control ring that can be assigned to adjust iris, exposure, or white balance. Autofocus is handled by STM motors, which Yates notes are smooth though slightly audible, which is something to keep in mind if you record video with an on-camera mic. The 67mm front filter thread is another small surprise given the bright aperture.

At f/1.2, this lens offers striking background separation and bokeh that looks cleaner than you’d expect from an entry-level design. The minimum focus distance of 45 cm isn’t class-leading, but it’s close to Canon’s more expensive 50mm f/1.2 and f/1.4 models. Optical design consists of nine elements in seven groups with nine aperture blades, and Canon’s Super Spectra coating reduces flare and ghosting effectively. Yates points out some mild double edging in out-of-focus highlights but still calls the rendering impressive for the price. Early tests show this lens producing sharp results even wide open, with little difference in real-world sharpness between f/1.2 and f/5.6 in center regions. Corner performance softens slightly at wide apertures, which is expected, but the overall image holds up better than many lenses in its price category.

Key Specs

• Focal Length: 45mm

• Maximum Aperture: f/1.2

• Minimum Aperture: f/16

• Mount: Canon RF

• Format: Full frame

• Minimum Focus Distance: 1.5' / 45 cm

• Magnification: 0.13x

• Optical Design: 9 elements in 7 groups

• Aperture Blades: 9

• Image Stabilization: No

• Filter Size: 67 mm

• Dimensions: ø 78 x L 75 mm

• Weight: 12.2 oz / 346 g

Yates runs a quick focus breathing test and finds that the lens does show noticeable breathing, but Canon confirms it supports focus breathing compensation on compatible cameras. The STM system isn’t as fast or silent as Nano USM or VCM motors, yet it performs steadily for both stills and video. In his autofocus tests, Yates walks toward and away from the camera while the lens tracks him at f/1.2, holding focus accurately with minimal pulsing. The lens vibrates slightly when focusing, which is typical for STM designs, but it’s unlikely to affect handheld use.

The standout aspect is value. Yates calls the 45mm f/1.2 STM a lens that “punches above its weight.” The combination of shallow depth of field, solid sharpness, and manageable size makes it appealing whether you shoot portraits, street, or general lifestyle content. It’s rare to find an f/1.2 prime that feels this approachable, both in price and handling. Check out the video above for the full rundown from Yates.