Get all your news in one place.
100's of premium titles.
One app.
Start reading
Digital Camera World
Digital Camera World
James Artaius

Canon RF 45mm f/1.2 STM review: The super-fast glass that's super affordable –and punches way above its weight and price point

Canon RF 45mm f/1.2 STM product image.

I'm a bokeh whore, so the Canon RF 45mm f/1.2 STM won me over on its aperture alone. But when I saw the price that goes along with it, this lens became an absolute no-brainer.

As someone who has spent far too much money on some of the fastest camera lenses you can buy – including Canon's flagship f/1.2L glass that costs thousands of dollars along with multiple cheap but chunky Chinese f/0.95 optics with no autofocus – the Canon RF 45mm f/1.2 STM feels like a lens that was tailor-made for people like me.

If you're someone who loves fast glass, whether it's to get the blurriest backgrounds or to work in low light, the fact that you can get an f/1.2 optic with autofocus for less than 500 bucks makes this truly phenomenal bang for your buck. And if you're an APS-C shooter, it's an equivalent 72mm f/1.2 that's perfect for portraiture. Sounds too good to be true? Let's see...

Not much of a handful, the RF 45mm is refreshingly compact and lightweight for an f/1.2 prime. (Image credit: Matthew Richards)

Canon RF 45mm f/1.2 STM: Specifications

Mount

Canon RF

APS-C equivalent focal length

72mm

Image stabilization

N/A

Weather sealing

N/A

Focus

Auto, Manual

Control ring

Yes (clicked)

Aperture ring

No

Lens construction

9 elements (1 PMo Aspherical), 7 groups, 9-blade aperture, Super Spectra Coating

Minimum aperture

f/16

Minimum focus distance

0.45m

Maximum magnification

0.13x

Filter size

67mm

Dimensions (D x L)

78 x 75mm

Weight

346g

Canon RF 45mm f/1.2 STM: Price and availability

As impressive as the aperture itself, the Canon RF 45mm f/1.2 STM boasts an incredible price tag of just $469 / £479.99 / AU$699.95.

For comparison, the slower but similarly budget-priced Canon RF 50mm f/1.8 STM clocks in at $239 / £197 / AU$294, the Canon RF 50mm f/1.4L VCM photo-video hybrid costs $1,399 / £1,539 / AU$1,839, while the flagship Canon RF 50mm f/1.2L USM with the same aperture comes in at $2,599 / £2,449 / AU£3,261.

Similar third-party lenses are available, such as the Irix 45mm f/1.4 at $825 or the Brightin Star 50mm f/0.95 for $399, but they are both much larger and lack any autofocus capability.

Canon RF 45mm f/1.2 STM: Design and handling

The Canon RF 45mm f/1.2 STM is part of the company's enthusiast range, which includes the likes of the Canon RF 85mm f/2 IS Macro and the RF 50mm f/1.8 to which many will be comparing this lens. This means that, while you don't get weather-sealing, you still get a lens with impressive construction that's great for day-to-day shooting.

Like other RF glass, it comes with a customizable control ring on the nose – which can be set to manipulate exposure values or other camera functions. However, unlike the RF 50mm f/1.8, the Canon RF 45mm f/1.2 STM also features a separate and satisfyingly chunky manual control ring – which you'll certainly need, if you're trying to hand-focus at the razor-thin f/1.2 depth of field. Personally, I'd leave the AF / MF switch set to autofocus!

Understandably, given the size of the elements required for such a fast aperture, the RF 45mm is quite a bit bigger than the RF 50mm f/1.8 – but it's still surprisingly small at just 75mm in length.

The Canon RF 50mm f/1.8 STM (left) is smaller than the Canon RF 45mm f/1.2 STM (right), but it's also slower and doesn't have a dedicated manual focus ring (Image credit: James Artaius)
The Canon 45mm RF f/1.2 STM (left) has the same maximum aperture as the Canon RF 50mm 50mm f/1.2L (right), though lacks weather sealing and L-series optical performance (Image credit: James Artaius)

It's drastically smaller and lighter than the behemoth RF 50mm f/1.2L, despite both lenses possessing the same speed, although obviously you're not getting the L-series weather sealing or pristine optical engineering (more on that later).

Again, as someone who owns a bunch of third-party fast glass – including the Mitakon Speedmaster RF 50mm f/0.95, which weighs 720g (and the EF version that tips the scaled at 1,500g!) – the fact that the Canon RF 45mm f/1.2 STM weighs a paltry 346g is truly remarkable.

Onboard controls include an AF/MF focus mode switch, a comfortably large manual focus ring and a click-step customizable control ring at the front of the lens. (Image credit: Matthew Richards)

Its size and weight make it a suitable companion for just about any camera in the EOS R family – including super small bodies like the Canon EOS R50 V, where it's a far better match than the hulking great RF 50mm f/1.2L. Indeed, some shooters find the RF 50mm f/1.8 to be too small – particularly since it doesn't have a dedicated manual focus ring.

By contrast the RF 45mm feels "just right", being perfectly cuppable in the crook of even large hands without feeling oversized like its f/1.2L bigger brother. It really is a pleasurable lens to hold and handle, whichever body you're using it with.

If you need speed, the Canon RF 45mm f/1.2 STM is much more manageable on small bodies like the Canon EOS R50 V than the larger 50mm f/1.2L (Image credit: James Artaius)

Unlike some budget-friendly lenses, the RF 45mm has a metal rather than plastic that should prove perfectly durable. The mount features gold-plated electronic contacts but lacks a rubber weather-seal ring.

Plus points include a metal mounting plate with gold-plated electronic contacts but there's no weather-seal ring to resist the ingress of dust and moisture. (Image credit: Matthew Richards)

Canon RF 45mm f/1.2 STM: Performance

As someone who owns and loves the RF 50mm f/1.8, and given the similarity in focal length and (just about) price, I'm pretty sure everyone reading this review is wondering how the two lenses directly compare. In a nutshell, if I didn't already own the 50mm f/1.8 (and those Chinese f/0.95 lenses) I would buy the Canon RF 45mm f/1.2 STM instead.

Optical performance is impressive even when shooting wide open, with good clarity and center-sharpness, although edge/corner-sharpness is disappointing at apertures wider than f/2.8. Bokeh / background blur / subject separation is pleasing, on the whole. If you're wondering what the difference is between f/1.2 and f/1.8 (ignoring the 5mm difference in focal length), I took a couple of side-by-side comparisons to illustrate:

How much blurrier is f/1.2? On the left is the RF 45mm f/1.2 at its widest aperture, on the right is the RF 50mm f/1.8 wide open, shooting a subject close up (Image credit: James Artaius)
And here's a portrait setting, again with the RF 45mm f/1.2 at its widest aperture on the left and the RF 50mm f/1.8 wide open on the right (Image credit: James Artaius)

The difference in bokeh and separation is a little more pronounced when shooting on an APS-C sensor (bodies like the EOS R50 and EOS R10), where the equivalent focal length becomes 72mm – putting this lens in portrait territory. As you can see from the sharpness of my whiskers and eyebrows above (sorry for not scrubbing up a bit more!) this is plenty sharp enough for portraiture.

While we're doing some comparisons, it's worth noting that the Canon RF 45mm f/1.2 STM relies on in-camera corrections to do some of the heavy lifting – and it's here that the real differences between this lens and the L-series 50mm f/1.4 VCM and f/1.2L USM start to become apparent.

As. you can see in the RAW image below, there's a notable amount of barrel distortion and vignetting straight out of camera. Of course, the camera corrects the effect and it's only a couple of clicks to fix it in post production if you're someone who works from your RAWs – but it's something to be aware of. You'll also notice some fringing, which you'll need to correct manually.

You can see the degree of in-camera correction at play between the JPEG (top) and the original RAW file (bottom) (Image credit: James Artaius)

For another test, my colleague shot the following gallery of images of a phrenology head against a garden background, which serves a variety of purposes. Taken at all major aperture steps between f/1.2 and f/11, you can gauge sharpness levels on the fine text and lines of the head, as well as the quality of bokeh in the background. The composition also draws attention to any axial chromatic aberration (bokeh fringing) around high-contrast transitions just in front of or behind the plane of focus, which can be problematic for fast lenses at or near their widest aperture.

Obviously, there is a world of difference between the Canon RF 45mm f/1.2 STM and the 50mm L-series alternatives in terms of pure optical performance – and nowhere is this more apparent than the bokeh.

As you'll see in the first image of geese in the samples below, the 45mm has quite a Petzval effect – characterized by "swirling" at the periphery of the image. In the image of the Portuguese chicken statue, you'll notice "cat's eye" bokeh balls (shaped more like a lemon than a perfect circle) again at the edges of the frame.

And in the second image of geese, in addition to the Petzval effect, you'll see that the specular highlights on the hedge are creating "soap bubble" bokeh balls (with a thin bright ring around a pale center).

While some shooters love the swirly bokeh effect (and even buy special Petzval lenses to achieve it), it and the other characteristics are generally regarded as "noisy bokeh" – and may or may not be to your liking. The L-series optics have much smoother "creamier" bokeh, which is the result of a more complex (and expensive) optical formula.

I'm not here to tell you what's best. You might well prefer the "noisier" look! But I can tell you that I think the quality of the blur is better on the Canon RF 45mm f/1.2 STM than on the RF 50mm f/1.8 – and this lens is more than good enough to shoot wide open while retaining sharpness and detail, certainly in the center of the frame.

Canon EOS R5 + Canon RF 45mm f/1.2 STM (1/20 sec, f/1.2, ISO250) (Image credit: James Artaius)
Canon EOS R5 + Canon RF 45mm f/1.2 STM (1/4000 sec, f/1.2, ISO100) (Image credit: James Artaius)
Canon EOS R5 + Canon RF 45mm f/1.2 STM (1/20 sec, f/1.2, ISO125) (Image credit: James Artaius)

Canon RF 45mm f/1.2 STM: Sample images

The gallery of example shots below was taken outdoors, on an overcast morning in the English city of Bath, as well as in the city’s indoor market and a local bookshop. I used a medium aperture setting for some of the shots, and the widest available aperture of f/1.2 for others.

Canon RF 45mm f/1.2 STM: Lab Results

We run a range of lab tests under controlled conditions, using the Imatest Master testing suite. Photos of test charts are taken across the range of apertures and zooms (where available), then analyzed for sharpness, distortion and chromatic aberrations.

We use Imatest SFR (spatial frequency response) charts and analysis software to plot lens resolution at the center of the image frame, corners and mid-point distances, across the range of aperture settings and, with zoom lenses, at four different focal lengths. The tests also measure distortion and color fringing (chromatic aberration).

Sharpness:

(Image credit: Future)

Center-sharpness is satisfying even when shooting wide-open at f/1.2, and improves further when stopping down to apertures of between f/2 and f/11. Away from the central region of the frame, sharpness is lackluster at apertures wider than f/2.8, and quite disappointing towards the edges and corners.

Fringing:

(Image credit: Future)

Color fringing can be a little noticeable towards the edges and corners of the image frame but is nevertheless of quite a low order and easily within the remit of automatic in-camera correction.

Distortion: -5.23

Like many modern lenses designed for mirrorless cameras, especially with compactness and lightness of weight in mind, the RF 45mm suffers from severe native distortion, with a very pronounced barrel effect. Automatic in-camera correction is relied upon to straighten things out.

Canon RF 45mm f/1.2 STM: Verdict

I think the Canon RF 45mm f/1.2 STM is brilliant little lens that's going to sell like gangbusters. While the RF 50mm f/1.8 is always going to reign as the cheapest and almost-smallest lens in the lineup, for a couple of hundred bucks more the 45mm is the better option.

Its optical performance is on par but you get significantly better light transmission and background blur / subject separation, making this a superior option both creatively and in terms of working in low light. The only real fly in the ointment is that edge/corner-sharpness is disappointing at wide apertures, but that's a moot point if you're more interested in subject separation and bokeh.

The actual quality of bokeh isn't as smooth as the more expensive L-series lenses, but you are literally adding another grand for the 50mm f/1.4L and another grand on top of that for the 50mm f/1.2L. It is, however, more bokehlicious than the 50mm f/1.8 – which is the Canon RF lens that this one is really competing with.

Moreover, I prefer this lens to third-party f/1.2 and f/0.95 lenses that I've tried from Chinese manufacturers – most of which are more expensive, all of which are bigger and heavier, and none of which have autofocus, which severely limits their usefulness when working at super shallow depths of field.

And again, if you're an APS-C shooter this becomes a fantastic proposition for portraiture – an effective 72mm f/1.2 being a powerful portrait tool.

Whether you're an RF or RF-S shooter, whether you care about bokeh or you just want a more useful lens, the Canon RF 45mm f/1.2 STM might just be the smartest buy in the entire RF lineup. Maybe Canon doesn't need Sigma and co after all to make exotic lenses…

Features

★★★★☆

Top of the list is the super-speedy f/1.2 aperture rating but there’s not much else in the way of fancy features and you even have to buy the hood separately.

Design

★★★★★

Proving that actually can squeeze a quart into a pint pot, Canon has succeeded in combining a 45mm focal length with an f/1.2 aperture into a remarkably compact and lightweight build.

Performance

★★★★☆

Image quality relies to some extent on automatic in-camera corrections and wide-aperture edge-sharpness is disappointing but the net results are very satisfying overall.

Value

★★★★★

For an own-brand Canon f/1.2 prime lens, this one is insanely great value for money.

Alternatives

Sign up to read this article
Read news from 100's of titles, curated specifically for you.
Already a member? Sign in here
Related Stories
Top stories on inkl right now
One subscription that gives you access to news from hundreds of sites
Already a member? Sign in here
Our Picks
Fourteen days free
Download the app
One app. One membership.
100+ trusted global sources.