f/1.2 on a Budget: What You Gain and What Breaks

Cheap and f/1.2 rarely belong in the same sentence. This video puts that combination in a real shoot to see what breaks first.

Coming to you from Julia Trotti, this practical video puts the Canon 45mm f/1.2 STM lens through a real portrait session instead of a lab-style chart test. Trotti shoots it on a Canon EOS R6 Mark III and shows unedited frames at 100% so you can judge sharpness without guessing what editing hid. You see how the lens renders skin texture and hair detail when focus lands where it should, and you also see where it falls short compared to pricier RF options. The most useful part is the way she separates “looks sharp” from “is sharp,” because an f/1.2 prime can fool you on a quick preview. She also flags a look you may like right away: soft, creamy backgrounds with a smooth focus transition that flatters close-ups.

Trotti doesn’t pretend optical quirks don’t exist, and that’s where this gets practical. She points out strong vignetting and some distortion in the unedited images, then shows how lens corrections clean it up in Lightroom, which matters if you expect straight lines to stay straight. She also spends time on autofocus in video mode, using human detection and fast AF settings, then shows the slip when subjects start moving. If you shoot kids, couples, or anything with motion, the hit rate matters more than the prettiest bokeh sample. The lens uses a stepping motor, and her footage makes it clear you’ll get “good enough” focus for slower portrait work, plus more misses as movement picks up. She still ends the day with a workable set of keepers, which is the kind of detail you can map to your own tolerance for missed frames.

Key Specs

• Focal length: 45mm

• Maximum aperture: f/1.2

• Minimum aperture: f/16

• Mount: Canon RF

• Format coverage: full frame

• Minimum focus distance (from sensor): 1.5 ft / 45 cm

• Maximum magnification: 0.13x (1:7.7)

• Optical design: 9 elements in 7 groups

• Diaphragm blades: 9

• Focus: autofocus

• Image stabilization: none

• Filter thread: 67 mm

• Weight: 12.2 oz / 346 g

The build section is where you’ll start making tradeoffs in your head. Trotti notes the small size for an f/1.2, the control ring, the 67mm filter thread, and the lack of dust and moisture resistance, which pushes you to think about weather-sealing and risk. She also talks about bokeh shape: cleaner circles without onion rings, some cat-eye shapes wide open, and rounder highlights as you stop down toward f/1.6, then harder edges showing up around f/4. You get both soft flare that blends and stronger, more defined flare that can take over a frame. Chromatic aberration shows up too, and while software can reduce it, she shows a case where heavy correction can leave distracting outlines around blurred edges. Near the end, she compares the lens against nearby options like the Canon RF35mm F1.8 Macro IS STM and the Canon RF50mm F1.8 STM, and she frames it as a first serious prime if you want shallow depth of field without paying for top-tier glass. She even ties it back to the role a classic fifty used to play, referencing the Canon EF 50mm f/1.4 USM as the kind of “one lens for a year” choice that forces you to learn framing and timing. Check out the video above for the full rundown from Trotti.