Before I dig into the nitty-gritty of how this lens performs, I think it’s important to answer the question, “why did I buy this lens?”  There are two main reasons:  First and foremost, I purchased this lens because of my experience over the past couple of years with the Voigtländer Nokton RF 50mm f1.0 (previously review here on ThruMyLens).  I picked it up in March of 2024 – believe it or not, it was my first ever 50mm prime up to that point.  And despite that fact that I still don’t really consider myself a 50mm guy, I absolutely fell in love with this lens.  And while I may not be a 50mm guy, I’m most definitely a 35mm guy.  Since picking up the 50mm f1.0, I hoped that Voigtländer would eventual port over one of their manual 35mm f1.2 lenses to the RF mount.  Alas, they’ve essentially had the same three RF lenses in the Voigtländer catalog for quite some time.  The aforementioned 50mm f1.0, the 75mm f1.5, and the 40mm f1.2, which is of course the subject of this review.

The second reason I (finally) picked up the Voigtländer Nokton RF 40mm f/1.2 is that you currently can’t buy a 35mm f1.2 for the Canon RF platform…from any manufacturer.  I currently own the Canon EF 35mm f1.4.  The image quality is phenomenal – better IMHO than the Canon 35mm f1.4 VCM lens that came out in 2024 (a lens I plan to test later this year).  The only problems I have with it are 1)it’s big/heavy (especially with the EF to RF adaptor) and 2)It’s not f1.2.  Rumor had it that Canon was coming out with an RF 35mm f1.2…but instead we got the RF 35mm f1.4VCM.  You can imagine my disappointment.   I’m not getting any younger (or more patient) and I couldn’t wait any longer.  I found a great deal on a pre-loved Voigtländer Nokton RF 40mm f/1.2 from Map Camera in Tokyo (where I ordered the 50mm f1.0 from nearly two years ago) and placed my order.

THE 40mm FOCAL LENGTH

The reason why I’m not crazy about 50mm as a focal length is that I have a harder time composing with it.  In some cases, it’s simply too zoomy for the type of photography I do.  Take for example the local Cars & Coffee events I like to attend in the summer months.  If I want to get the entirety of a car in frame, I often can’t back up enough in a parking lot before hitting the row of cars behind me to get the composition I want.  I never have that problem with 35mm.  Would the 40mm focal length be wide enough for my needs?  I know some people swear by the 40mm focal length, so I was certainly curious what my experience would be.  To alleviate my concern, I decided my first test photos taken with the Voigtländer Nokton RF 40mm f/1.2 (mounted on my Canon R6 Mark III) would be to compare them with shots taken with my Canon EF 35mm f1.4 (mounted on my Canon R5 Mark II) and determine just how big of a deal the ~5mm difference in focal length would be.  For giggles, I decided to also throw my Voigtländer Nokton RF 50mm f1.0 into the mix as well.

The reality is that the 40mm f1.2 was probably easy for both Canon to approve on the RF mount, and Voigtlander to produce.  Canon doesn’t have a 40mm lens in their catalog – which made it much easier to say yes to Voigtländer to produce versus say a 35mm lens.  Voigtländer on the other hand has been producing 40mm lenses for years and had one “on the shelf” that was relatively easy to produced with the new RF mount.

Manual Focus, But Not “Dumb” Manual Focus

One of the most important things to understand about this lens is that it’s not a fully mechanical throwback.  Canon approved Voigtländer to manufacturer the lens and implement electronic communication with RF bodies, and that matters more than you might expect.

You get:

• Full EXIF data
• Focus confirmation
• Lens recognition in-camera

That combination changes the shooting experience dramatically. You’re still manually focusing, but you’re not flying blind.  Canon has two distinctly different methods to assist users in getting correct focus – Focus Peaking and Focus Guide.  Focus peaking is similar to other manufacturers manual focus assist coloring the in-focus are in red (or blue)  in the display.  Focus Guide is better.  You’ll see two arrows in the display – simply line up the arrows and the focus area marked with the focus box will be in-focus.  Only lenses that are approved by Canon for the RF mount like this Voigtländer lens will communicate with the camera body and provide the Focus Guide option.

Image Quality and Rendering

To be honest, wide open at f/1.2, the Voigtländer is not clinically perfect — and that’s not a flaw in my book. Sharpness is strong in the center with gradual falloff toward the edges, contrast is solid without being harsh, and out-of-focus areas have a smooth, organic transition that avoids the nervous rendering some ultra-fast lenses exhibit.  This is a lens that prioritizes character over lab-chart perfection. Highlights roll off naturally. Backgrounds dissolve rather than smear. Subject separation feels dimensional without looking artificially exaggerated.  Stopped down slightly, sharpness improves across the frame, but the real appeal of this lens is clearly its wide-open behavior. If you’re buying this lens to shoot at f/4, you’re missing the point.

Do images taken with this lens exhibit some vignetting?  Yep.  Do images also exhibit LoCA (lateral chromatic abortions and longitudinal abortions?  Some, yes – not at all uncommon with fast manual lenses like this one.  But if you’re extremely sensitive to vignetting and/or color fringing, it’s something to be aware of before purchasing.

Here are some images I took with the lens, mounted to my Canon R6 Mark III.  I also brought along my Canon R5 Mark II and used both the Canon EF 35mm f1.4 as well as the Voigtländer Nokton RF 50mm f1.0.  I brought these other lenses to take comparison images to answer two questions.  First, just how close to the 35mm field of view is this 40mm lens?  Second, do I really need the 50mm if I have the 40mm.  Note that the images will be straight out of the camera with only minor adjustments to exposure, unless otherwise noted, to allow for better comparison.

Voigtländer vs. Voigtländer

Here’s a scene I took with both the Voigtländer Nokton RF 40mm f1.2 and the Voigtländer Nokton RF 50mm f1.0:

 

 

The first image, taken at 50mm, feels more compressed and more tightly focused on the planter. You can also see a noticeable amount of natural vignetting, which further pulls your eye toward the subject. The result is a more dramatic, spotlight-style rendering where the planter dominates the frame.

The second image, shot at 40mm, tells more of a story. There’s more of the surrounding environment — the side of the building, the sidewalk, and even the sign above the window — all contributing context, even though they’re rendered softly out of focus. The subject still stands out clearly, but it exists within a place rather than being isolated from it.

In terms of pure image quality, the two lenses are very comparable. The background blur is stronger in the 50mm shot due to both the longer focal length and increased compression, which enhances subject isolation and gives the image a more cinematic look. The 40mm, by contrast, trades some of that intensity for a more natural, narrative-driven perspective.

Focus on the planter is nailed in both photos — a great example of how Canon’s Focus Guide makes manual focusing at f/1.2 far more reliable than you might expect.

What really becomes clear in this comparison is that these two lenses aren’t interchangeable. You couldn’t simply crop the 40mm image to recreate what the 50mm delivers. The difference isn’t just framing — it’s perspective, compression, and how the scene itself is rendered.

Next I started taking some photos comparing the Voigtländer 40mm lens with my Canon EF 35mm f1.4.  I found a vehicle parked on the street and photographed it standing in the same position with both lenses:

 

Both frames show essentially the same composition: a Jeep in the foreground, downtown Miamisburg stretching behind it, with the Plaza Theater sign anchoring the scene. On paper, 35mm and 40mm shouldn’t feel dramatically different — but here they absolutely do.

This was an especially important comparison for me, because I shoot a lot of automotive photography in the summer. In this pair, the 40mm shot spotlights the Jeep more effectively, yet still preserves enough of the background to give the scene context. It isolates the subject without losing the story — a balance I find far more engaging.

By comparison, the 35mm frame feels flatter and more ordinary. The Jeep stands out primarily because it’s in focus, not because the composition or rendering gives it visual priority. The amount of background blur is actually fairly similar in both images, but the 40mm introduces slightly brighter, more pronounced highlights in the background — especially around the blue building — along with more visible vignetting, which further draws the eye toward the subject.

The takeaway isn’t that the 40mm Nokton replaces a 35mm lens. It doesn’t. Instead, it changes how a scene feels — tightening the composition, increasing subject separation, and giving images a more deliberate, less documentary-style rendering.

The 27 degree Ohio weather in January got the best of me and I dashed into Granpa Joe’s Candy Shop.  While I was warming up I noticed how great the lighting was in the store, and how colorful the shelves were – I had stumbled upon a fantastic location for test photos – the store manager happily allowed me to photograph in the store.  I started with the soda display:

 

I like all three of these images a great deal — and scenes like this are where Canon color science really shines.  The saturated bottles, glass reflections, and mixed lighting produce rich, vibrant files straight out of camera, and both lenses render the scene beautifully.

Much of what we saw in the previous street comparison applies here as well. The 35mm frame has a more photo-journalistic feel.  It shows the wall as it is, cleanly and evenly, without drawing too much attention to itself as a lens.  It documents the scene.

The 40mm images, by contrast, feel more artistic.  The natural vignetting and slightly tighter field of view give the soda wall more visual depth and draw the eye toward the center of the frame.  The shelves feel less like a catalog and more like a composition.

If that vignetting isn’t always to your taste, it’s easily controlled in Lightroom.  The Voigtländer RF 40mm f/1.2 has a lens correction profile, and applying it quickly reduces or eliminates the darkening in the corners, as shown in the corrected version here.  That gives you the option to either lean into the lens’s character or dial it back, depending on the image:

Here’s a photo I shot of a display in the foreground, with the store entrance in the background:

 

Three things stand out immediately in this comparison:

The first is just how sharp the Voigtländer 40mm is at f/1.2. Even wide open, the point of focus on the display is crisp and well-defined — this is not a soft, dreamy f/1.2 lens.

The second is how the two lenses handle highlights. In the 35mm image, you can clearly see detail outside the front door, while in the 40mm frame those highlights are completely blown out. Whether that’s good or bad depends on intent. Blown highlights remove choice from the photographer, but in this case the outside detail only distracts from the display itself, so the 40mm’s more aggressive rendering actually works in its favor here.

The third is how quickly focus falls off. Background blur is strong and vignetting is pronounced, both of which further isolate the center of the frame. As with the earlier examples, that vignetting is easily corrected in Lightroom, but here it serves a useful purpose. If this were a merchandising or product-highlighting shot — new items, promotions, or a featured display — the way the 40mm draws attention to the center could be a creative advantage rather than a flaw.

That said, this scene also shows where the 35mm still has the edge. At this working distance and with this type of subject, the wider field of view provides more headroom and more even coverage across the frame. The display, the surrounding shelves, and the overall space read more naturally.

When I’m taking photos inside a business, I’m careful not to get any customers or staff in frame.  But the store manager was very accommodating so I asked if any of the store personnel would mind or even like to get their photo taken and as luck would have it, I got a lucky volunteer.  Here’s the first set of portrait shots I took:

 

The Canon 35mm really shines here.  It captures a sharp, flattering portrait of the store employee while also preserving the atmosphere of the space.  This image is straight out of the camera, with no corrections applied, and it already looks finished — exposure, highlights, and color are all well balanced under the challenging overhead lighting.

The 40mm version takes a different approach.  Vignetting needs to be reduced, and the highlights — particularly on the illuminated sign and on the subject’s skin — need to be tamed.  With some work in Lightroom, you could bring it to the same level of polish as the Canon image, but it takes more effort to get there.

Compositionally, however, the 40mm has a subtle advantage. The tighter field of view naturally removes the distracting scale on the counter that appears in the 35mm frame, making the composition feel cleaner and more focused on the subject.

 

With this final set of images, choosing a favorite is genuinely difficult. Once again, the straight-out-of-camera Canon 35mm version looks excellent — balanced, natural, and immediately usable without any correction.

The 40mm image, by contrast, can be brought to the same level with careful editing, but it takes more skill and expertise. This is not a lens that a casual or beginner photographer will like – unless they have both the patience and willingness to learn.  Getting the best out of it requires understanding composition, exposure, highlights, and how to work with its vignetting rather than against it.

What I do like about the 40mm here is how that vignetting and tighter field of view draw attention to the subject.  The Canon frame feels busier by comparison, but it also tells a fuller story of the environment — the shop, the counter, the space the subject inhabits.

And that’s really the point. If the goal is to tell a story and convey atmosphere, the 35mm has the advantage.  If the goal is to present the subject in a more stylized, visually concentrated way within a colorful setting, the 40mm Nokton absolutely earns its place.

In the final analysis, the Voigtländer Nokton RF 40mm f/1.2  is both a fun and fantastic lens.  It’s diminutive form factor makes it ideal for an all-day walk around lens.  It’s got signature Voigtländer all-metal body construction that has vintage quality and good looks but still feels modern.  This lens provides a genuine alternative  to my EF 35mm f1.4 – but absolutely will not replace it.  I’m still waiting for Canon to come out with an RF 35mm f1.2 that can take its place with legendary RF lenses in the Canon catalog like the RF 50mm f1.2, and the RF 85mm f1.2.  But I suspect that I’ll be leaning into #that40mmlife in 2026.

Here’s my video review: