The “11873” – A review of the Light Lens Lab 35 mm f/1.4 double aspherical

There are a couple of things that I really love in regards to photography gear. Great build quality, great legacy, compactness, unique image quality, and a 35mm focal length. After spending close to three months with the Light Lens Lab 35 mm f/1.4 AA “11873” – hereafter referred to as the 11873 – I can wholeheartedly say that it checks all the boxes for me! It’s close to the best 35mm lens I’ve ever used, and that even include my absolute favourite lens of all time the Fujinon XF35mm f/1.4.

What I’ve always loved about great 35mm lenses is that they balance perspective, depth, and subject intimacy in a way few focal lengths can match. Obviously it has a wider FOV on full frame sensors than when adapted to APSC, but it’s my absolute go to focal length on both systems.

With the 11873 we see an ambitious attempt to recreate and refine one of the most legendary Leica optics of the late 20th century: The Leica Summilux-M 35 mm f/1.4 Double-Aspherical, which Leica gave the part number 11873. Hence the name of the Light Lens Lab version.

Unlike many derivative or generic 35 mm options, the 11873 isn’t about chasing peak resolution numbers. Instead it’s an engineering homage that Mr. Zhou and his team at LLL set out to bring to the masses. It’s a lens that strives to bring the special rendering, contrast, and philosophy of a rare classic into the hands of those who cannot afford the astronomical price of the original.

Disclaimers

Before we get going, let me post my usual disclaimers for good measure. 

Disclaimer 1: I was not paid, nor asked to make this post by Light Lens Lab. All opinions expressed in this article are my own. Light Lens Lab has not been sent this article before publication for review. 
Disclaimer 2: All images of, and from this lens have been taken by me and is not to be used or redistributed without my prior consent.
Disclaimer 3: I have a collaboration with Light Lens Lab to deliver product shots to them. It’s a paid collaboration. I am not expected to do these reviews, it’s not part of the terms of the collaboration, and I choose to do them at my own free will.

Background

Light Lens Lab’s mission has been clear since its inception: to rebuild optical designs that are historically significant, optically unique, and otherwise unobtainable for most photographers, all at a fraction of the price of the originals. My review of the Z21 found here is a great example of this.

The 11873 was introduced by Leica in the early 1990s as a Double Aspherical Summilux – the first 35mm f/1.4 from Leica to incorporate two aspherical elements. This was a serious engineering undertaking where the aspherical surfaces were hand-ground and hand-polished, a painstaking and failure-prone process that pushed the limits of manufacturing capability at the time. The result was a design that stood apart from other all other lenses back then. A rare optical path that featured concave aspherical elements both front and rear, something virtually unique even among Leica lenses. 

Traditional Leica documentation and compiled serial number records suggest production spans from roughly 1991 to 1994, with only a few thousand units ever made – generally cited around 2,000 officially, with some historical builds and records hinting at up to 4,000 overall, including early runs. 

This brief production run, combined with the difficulty and low yield of manufacturing double aspherics, immediately made the lens uncommon. At the time, it was already expensive relative to other Leica glass, and over the decades that followed, it has become something much more than just another 35mm.

Collectors and Leica enthusiasts have since then looked at the 11873 with almost legendary status. Part of this comes from its optical character, its rendering at wide apertures, the way it transitions highlight to shadow, and the subtle “glow” it produces that many find aesthetically pleasing even decades later. But that character alone does not fully explain the aura the lens now carries.

The far larger factor is scarcity and human context. A lens that was painstakingly hand-made, available for a very short period, and never mass-produced. Every intact example that surfaces today – especially with original hood, caps, and box – are sold at insane prices.

Layers of rarity have further accumulated on the margins of the collector market; for example, a unique prototype brass-body silver chrome 11873 recently listed at eye-popping value. Usually these lenses go on sale on auctions and e-bay listings. Prices for clean, complete examples with hood and caps typically range in the mid-five figures in euros, with recent hammer prices around ~€15,000–€19,000!!!

The Light Lens Lab 35mm f/1.4 AA “11873” launch, therefore, isn’t just about “another 35 mm lens”; it’s about bringing a historically important optical concept back into circulation, but refined for the demands of high-resolution digital sensors and with modern manufacturing precision – and most importantly – at a pricepoint where mere mortals can actually get to try out this special optical formula.

Design Philosophy & Optics

Technically, Light Lens Lab has taken the original double-aspherical premise and refined it for modern standards, not just 1:1 copied it. The optical formula remains 9 elements in 5 groups, with double-aspherical surfaces in both Group 2 and Group 5 — mirroring the classic double-aspherical structure.

However, modern refinements include:

– Molded and polished aspherical elements, improving production precision and consistency compared with purely hand-polished vintage glass.
– Integration of Extra-Low Dispersion (ED) and achromatic elements to suppress chromatic aberrations and distortion beyond what the original could realistically manage.
– Lanthanide-infused glass to help retain that classic, controlled “glow” at wide apertures while still aligning with digital sensor characteristics.
– Extended rear element spacing, which improves performance on high-resolution digital sensors by optimizing the optical path — a consideration not present when the original was designed for film.

These changes illustrate a key point: the 11873 isn’t a 1:1 replica that simply copies measurements. It’s a reinterpretation that wants to preserve the original character while mitigating classic limitations (like excessive chromatic aberration and flare) and adopting materials that Leica never could back then.

Build and Feel

The 11873 feels EXACTLY like a Leica lens. There’s absolutely no visual or build quality difference. I actually think that the focus and the aperture is actually better than my 35mm f/1.4 Summilux FLE. In true Light Lens Lab fashion, this is veeeery different from other third-party prime manufacturers. Light Lens Lab has designed, manufactured, and assembled every optical and mechanical component in-house, ensuring uniform standards across production, and it’s done to a VERY high standard. I cannot stress this part enough. It’s very impressive.

The 11873 comes in 3 versions. A limited edition titanium run, that I have used mostly. And an aluminum build with a black paint finish and an anodized silver chrome finish.  

Both the Black Paint and Chrome finishes share the same core construction:

They’re built out of aircraft-grade aluminium alloy for barrel, focus ring, and aperture components, chosen for strength, weight optimization, and corrosion resistance.  Total weight ~278 g, compact enough to remain balanced on an M-mount body without feeling front-heavy.  Dimensions: ~43 mm on camera, ~56.2 mm actual length, 52.9 mm wide. 

Black Paint is beautiful!! Surprisingly so. It emphasizes a stealthy, understated aesthetic that just looks and feels insanely good. Chrome offers a classic, reflective metal finish that many rangefinder shooters prefer for vintage-style rigs. I personally am a sucker for the silver on black body combo. Mechanically, there is no difference in optical formula or performance between these two aluminum finishes — they are functionally identical, differing only in materials finish. 

A significant structural variation is the Limited edition Titanium version. It’s a titanium alloy barrel and titanium accessory elements, raising the weight slightly to ~300 g – about 20 g more than the aluminum versions.  Titanium is inherently more rigid and corrosion-resistant, with a premium tactile feel often associated with high-end Leica special editions.  My Titanium edition shipped with a matching titanium E46 UV filter and a special Titanium 12587 lens hood, setting it apart in accessory quality. 

The titanium version is goooooorgeous. Probably the best looking lens I own.

All colors include a classic style squarehood with a cutout top right to minimize the rangefinder blockage. These hoods come in matching colors for the silver and black, where as the titanium version includes a black square hood, as well as that special edition “tulip” round hood in titanium. It’s gorgeous!
A note. My initial square lens hood that came with the titanium edition had a slightly loose fit causing some rattle. I bent the little tabs slightly for a tight fit. On the silver and black versions launched february 1st, this issue was fixed.

Mechanically, all versions deliver a well-executed rangefinder-friendly experience:

Aperture has a clicked diaphragm with half-stop clicks that are perfectly firm, ensuring precise control, preventing accidental adjustments during shooting.
The 10-blade aperture yields smooth, rounded out-of-focus highlights at some f-stops. The blades has a special curvature making the OOF specular highlights not entirely round through the apertures. At f/9 it’s almost star shaped, which make f/9 the perfect setting for gorgeous sunstars. Something that this lens does amazinly well even at f/2! – At f/11 and f/16 it’s perfectly round again. Minimum focus distance is 0.7 m, closer than many classic Leica 35 mm f/1.4s, yet obviously not as close as Leicas newer 35mm variants that go beyond the rangefinder coupling all the way to 0.5m.

The focus ring has enough resistance to avoid accidental shifts. My titanium version felt slightly stiff at first, loosening subtly as I used it the first couple of months. The black and silver versions seems to have been loosened slightly from the factory. Although I have yet to confirm that this is actually so.

Across all three finishes, the focus throw and detent feel are consistent. No version feels “looser” or sloppier than another. The titanium’s slight added mass can make focus rotation feel marginally smoother due to inertia, but the functional experience is fundamentally the same. 

On my Leica M-P240, Leica M9, Konica Hexar RF and adaped to my Fujifilm X-Pro3, the 11873 balances perfectly. – Not too long nor too front-heavy – And it looks freaking amazing. Especially the Titanium on titanium X-Pro3 looks very good.

Because the lens is not 6-bit coded, Leica bodies won’t automatically recognize it for metadata.

Image Quality

There’s no doubt that the build, feel and look of the 11873 is amazing – But lets look at what’s really important. Image quality!

It’s definitely where the 11873 most clearly reveals its intent. This is not a lens designed to win specification battles or to compete head-on with modern, highly corrected 35 mm optics like the Summilux-M 35 mm f/1.4 FLE or contemporary APO designs. Instead, its rendering is the result of deliberate optical priorities—priorities that place tonal continuity, spatial separation, and highlight behaviour ahead of absolute flat-field correction. It wants to get as close to the original Leica version, while improving on a few things along the way.

Understanding the image quality of the 11873 therefore requires looking at it across apertures, across the frame, and across use cases, rather than judging it by a single metric.

Wide Open at f/1.4 – This is its “signature rendering”

At f/1.4 center sharpness is good, but not assertive in the modern sense. Resolution is sufficient for contemporary digital sensors, yet it is accompanied by lower global contrast and a gentler transition from in-focus to out-of-focus areas.

This manifests as the characteristic “glow” often associated with the original Leica Double-Aspherical Summilux. Importantly, this glow is not caused by uncontrolled spherical aberration alone; rather, it appears as a combination of moderate residual spherical aberration, highlight bloom, and restrained micro-contrast. Fine details are present, but they are not aggressively separated from their tonal surroundings.

For portraits and close-range subjects, this is a very strong asset. Especially when adapted to Fujifilm crop sensors for a tighter crop. Skin tones retain continuity, edges are not harshly outlined, and specular highlights roll off smoothly, which is very much in line with its historical reference.

However, this also means that wide-open images can feel less immediately “snappy” than those from more modern lenses. Photographers expecting biting contrast at f/1.4 may find the rendering subdued. This is not a flaw as much as a consequence of design choices but it is a trade-off worth noting.

The 11873 does not pursue a flat field at wide apertures. At f/1.4, the mid-frame and edges show a noticeable drop in resolution and contrast compared to the center. Field curvature is present, and depending on subject distance, this can result in edges that appear softer even when technically within depth of field.

For environmental portraits, documentary work, or subject-centric compositions, this behaviour can actually enhance subject separation. The image subtly draws the eye inward, without the artificial emphasis of heavy vignetting or excessive contrast fall-off. It’s actually the same trait that gives the notorious Leica Noctilux lenses their very special appearance.

From f/2 and onward, the lens begins to exhibit higher contrast and improved resolution. By f/2.8, much of the wide-open glow has receded, and micro-contrast increases noticeably. Edges firm up, field curvature becomes less visually intrusive, and the lens begins to behave more like a general-purpose 35 mm.
What surpsied me was that at f/2 you actually get beautiful sunstar appearance from harsh ligh sources. Just look at the examples with the oncoming cars during nighttime shooting.

At f/4, the 11873 reaches what is arguably its most balanced state. Center and mid-frame sharpness is very good, edges are good, and contrast is more than sufficient. This aperture range is where the lens works particularly well for my street photography.

Beyond f/5.6, resolution continues to improve slightly, but the gains are incremental. The lens never becomes clinically sharp in the way modern APO designs do, but it does become very sharp and consistent.

Contrast and Tonal Rendering

One of the strongest traits of the 11873 is its tonal rendering. The lens excels at preserving mid-tone detail and maintaining smooth transitions between light and shadow. This is especially evident in black-and-white work, where the lens produces files with a natural, film-like tonal roll-off that requires minimal manipulation in post.

Global contrast is lower than modern Leica designs, particularly wide open, but local contrast improves quickly as the lens is stopped down. Importantly, contrast never feels artificially boosted. Even at f/4 and beyond, the lens avoids the brittle, over-defined look that can sometimes plague high-correction optics.

The trade-off is that images may require a modest contrast adjustment in post if a punchier look is desired. On the other hand, the files tolerate contrast increases well, without falling apart or introducing harsh transitions.

Bokeh and Out-of-Focus Rendering

Out-of-focus rendering is smooth, though not completely neutral. Background highlights tend to remain round thanks to the 10-blade aperture, but they can exhibit a slight internal texture.

There is mild outlining in certain high-contrast situations, and cat-eye shapes appear toward the edges of the frame when shot wide open. This is consistent with the optical design and again mirrors behaviour seen in the original Leica Double-Aspherical.

Foreground blur is generally softer than background blur, which contributes to a sense of depth and layering. Obviously being a 35mm, the lens does not dissolve backgrounds entirely. It maintains a degree of structure that can be either pleasing or distracting depending on subject matter.

Flare, Highlight Control, Aberrations & Vignetting

The 11873 shows a quite acceptable control over chromatic aberration and veiling flare, particularly on digital sensors. Longitudinal chromatic aberration is present at f/1.4, but it is moderate and generally easy to correct in post. I’ve seen samples from the original Leica 11873, and those images exhibit way more chromatic aberration than the LLL does. So they definitely improved this.

Backlit situations can still induce flare and highlight bloom, especially when strong light sources are near the frame edge. However, the behaviour is consistent and predictable. With both hood types mounted, contrast loss, and most flaring is better handled, though not eliminated.

Vignetting is present at f/1.4 – Around a stop of light near the corners. Nothing major, and nothing that isn’t to be expected with an M mount f/1.4 lens.

Reduction points

From a purely technical standpoint, several areas could be improved, though doing so would fundamentally change the lens’s character, so I’m not sure how valid these points are given the reason d’etre of this lens:

Wide-open edge performance is clearly behind modern standards. Lower contrast at f/1.4 may not suit photographers seeking “punch” straight out of camera. Field curvature limits use for flat subjects at wide apertures and bokeh neutrality is good but not class-leading.

But make no mistake. These are not oversights, they are the direct result of prioritizing rendering style as close to the original Leica lens as possible.

Conclusion and sample images

The Light Lens Lab 35 mm f/1.4 AA “11873” produces images that looks amazing. It has just the right amount of rendering flaws and strengths that it creates an almost perfect 35mm for my liking. There’s often talk about a lens’ character – And to me such character is much more important than clinical perfection. It’s what makes it fun for me to practice photography. The optical strengths of the 11873 lie in tonal continuity, spatial separation, and controlled imperfection.

Those looking for maximum sharpness, flat-field performance, and high contrast at all apertures will find better options elsewhere. But for photographers who value how an image transitions, rather than how sharply it resolves, the 11873 is exactly the lens to get.

I really have to applaud Light Lens Lab for taking this route of offering near exact replicas of these old mythical optics. It makes all the special traits of the bygone rarities available to all those of us who aren’t made out of money. The 11873 is the perfect example of this. It’s so well made, that you would mistake it for a real Leica lens any day of the week. The build quality, choice of materials and optical build and finish is world class and by a wide margin the best I’ve ever seen from any 3rd party manufacturer. Heck, it even beats most reputable brands in this regard.

Obviously this is a lens made for Leica M bodies, but it feels especially good when used on my Fujifilm X-Pro3. It pairs very very well with the physical size of the Xpro3, and furthermore the rendering of the lens looks really good when combined with the Fujifilm color science. Especially Acros and Classic Chrome. So if you’re a Fujifilm shooter and looking for a manual focus 35mm for your setup I would look no further.

The Light Lens Lab 35mm f/1.4 AA “11873” is an amazing lens, that I simply cannot recommend enough.

You can buy the 11873 by going to LightLensLab.com HERE

Sample images

All samples have been shot on the Leica M240 and M9 or the Fujifilm X-Pro3 with the Light Lens Lab 35mm f/1.4 AA “11873” lens. They are all RAF or DNG files that I have processed to my liking in Lightroom.