If you spend enough time behind a viewfinder, a specific focal length eventually stops being a choice and becomes your natural field of view. For me, that has always been the 50mm. It is the focal length of balance or at least, it should be.
My eternal quest for a prime 50mm is never just about resolving power, Although that is a major factor. It’s an ongoing search for a delicate, almost contradictory equilibrium. I want clinical, bite your tongue sharpness, but don't want an optic so harsh that it strips away personality. I want a butter smooth bokeh like I get from the Summilux Classic re-issue, but not at the expense of contrast. I want distinct character, micro contrast, and dynamic rendering, yet I expect the glass to hold its ground when pushed to its absolute wide open limits.
Lately, my search has centered around a familiar love hate relationship, the Leica Summilux M 50mm f/1.4 ASPH (Close Focus).
On paper and in the field, it is a magnificent piece of engineering. Its rendering is nothing short of gorgeous and deeply evocative, lifting subjects off the background with a signature look that makes images jump off the screen. But every time I evaluate my files, a persistent frustration creeps in, for all its aesthetic beauty, I continually feel it falls just a hair short in absolute, biting sharpness when I push it.
Is it user error, optical character, or simply the reality of squeezing modern resolution out of a rangefinder design? To find out, I put the Summilux to the test alongside two of the most formidable standard optics in production today which I personally own and use regularly. In fact, I use them a lot more than the Summilux because of that feeling of falling short:
The Voigtlander 50mm f/2 APO Lanthar ASPH
The Leica 50mm f/2 APO Summicron SL ASPH (L-mount)
Before diving in, one crucial detail needs to be clear, every single image in this comparison was shot entirely handheld.
When I shoot street or work on portraits out in the world, I don't carry or use a tripod. Testing glass locked down on a heavy studio rig might yield sterile bench data, but it doesn't reflect how I make photographs. This evaluation is strict real world usage, how these lenses perform right in your hands, in actual shooting scenarios.
To eliminate as many operational variables as possible and push each lens to its limits, primary testing was conducted on the Leica SL3-S, utilizing focus magnification to guarantee pinpoint focus. To complete the picture, I brought the Summilux back home to its native habitat mounting it on my M11 and putting it through its paces via both digital Live View and the traditional optical rangefinder.
While this isn't a lab bench chart test with sterile lines and test patterns, it gave me a definitive real world answer to where the Summilux stands among the giants of modern 50mm design.
Looking at this image, the overall atmosphere and color transition are undeniably beautiful. The roll off into the background pillows is silky and gradual, creating a lovely sense of depth. Just what you would expect from the Summilux.
However, when we turn our attention directly to the primary point of critical focus, the eyelashes, the exact issue which concerns me comes into view. The eyelashes are in the focal plane, but they lack that defined, razor sharp edge definition I so desire to see out of a $5500.00 lens. Instead of individual, crisp strands, there is a distinct glow and slight micro contrast drop around the lash line.
Critics might jump to motion blur given that this was shot handheld, but looking closely across the rest of the subject's features like the fine skin texture along the cheek or the strands of hair near the temple there are no double edges or directional trailing indicative of camera movement. The shutter speed was sufficient. What we are seeing is pure wide open optical behavior of the Summilux a characteristic spherical glow and softer micro contrast wide open that blurs the finest structural lines of the lashes, giving them a gentle, dreamy rendering rather than surgical resolution.
This was processed with DXO Photolab 9 and Filmpack 8. I applied the Fuji Velvi 50 preset to this image.
The Voigtlander 50mm f/2 APO Lanthar ASPH
The moment you switch to the APO Lanthar frame, the visual narrative changes completely right at the focal point.
Punching directly into the eyelashes, the difference is immediate. The fine, individual lash hair strands snap with razor sharp micro contrast and incredible edge definition. There is ZERO wide open haze or spherical softness here. The optical correction of the APO design renders every single lash cleanly separated, dark, and biting against the skin, revealing exact structural detail.
As for the background, being capped at f/2 versus f/1.4 does mean the background elements retain slightly more structure. Look closely at the dark green and beige cushions behind my daughter, the edges are just a fraction firmer than they were through the Summilux. However, the penalty in blur is nowhere near as drastic as the numbers might suggest on paper. The APO Lanthar's rendering remains smooth and natural, yielding a clean isolation without any distracting harshness or chromatic fringing in the OOF areas.
You lose a tiny slice of that ultra creamy f/1.4 background melt, but in exchange, you get absolute, uncompromising clarity right where your eye lands first.
Moving out to my garage setup, I found an intricate target, the fine synthetic tips on the right side of the paintbrush. High frequency details like thin bristles, metallic ferrules, and harsh background reflections immediately highlight where a lens excels or breaks down.
Summilux
Looking at the Summilux file, the overall color signature and atmosphere are characteristically warm and gentle. The yellow coiled hose and background elements melt away smoothly.
However, inspecting the key target area, the fine bristles on the upper right edge of the brush you can see that familiar spherical glow creeping in again. The individual bristle tips blend together slightly, surrounded by a soft halo rather than sharp separation. The text stamped on the metal ferrule lacks punch, and the overall contrast across the focal plane feels muted. It yields a pleasing, painterly rendering, but since I am looking for distinct, micro detailed separation on fine lines, it falls short of for me. It just doesn't have that modern clinical resolution.
Don't get me wrong. Its a fantastic lens that set a standard and is highly praised. I am just saying, for what I am looking for, it falls a little short.
Switching to the APO Lanthar, once again the jump in structural clarity is immediate. The individual bristles on the right side snap into focus with zero blooming or fringing around the fine white tips.
The micro contrast across the metallic ferrule and black rubberized handle rises dramatically compared to the Summilux. Because it is an f/2 lens, the yellow coiled air hose in the foreground retains slightly more edge structure, but the background highlights remain smooth and well behaved. The APO design does exactly what it promises, it eliminates chromatic aberrations and delivers raw, biting resolving power right at the point of focus.
The APO Summicron SL photo takes everything up a notch. It combines the extreme, surgical contrast of an apochromatic design with an almost three dimensional pop that makes the paintbrush jump off the frame. There is a reason why this lens is considered by many to be the best 50mm ever made.
Zooming into those right hand bristles, the edge definition is staggering. every single strand is rendered with total clarity, rich micro contrast, and zero optical haze. What makes the SL lens so remarkable here is how it manages the OOF areas. Despite being an f/2 lens, the transition from the ultra sharp focal plane into the background roll off feels distinctly smoother and more organic than the APO Lanthar, while matching (if not exceeding) its raw resolving power. It delivers razor precision without ever looking clinical or harsh.
A quick note of apology, in the flurry of working handheld in the garage, I completely missed capturing a matching frame for this specific focus point with the Voigtlander. Human error in real world testing! What can I say. We'll be evaluating this focus shift directly between the Summilux and the APO SL.
For this set, we shift the critical focus point down to the product label, specifically the UPC barcode and surrounding fine text sitting on the workbench. High contrast black and white lines like a barcode are absolute ruthless indicators of optical resolution, micro contrast, and wide open chromatic behavior.
Summilux
In the Summilux exposure, the overall scene maintains that smooth, gentle character across the foreground square and background tools.
Zooming in on the barcode label, the vertical lines and the small numerical text under the UPC are readable, but they carry a distinct soft edge. The black bars bleed slightly into the white gaps, creating a subtle lower contrast haze across the label. The fine print to the left of the barcode loses its crispness, appearing more like a continuous block of gray text rather than individual, razor sharp letters. It works fine at a distance, but punched in, the lack of biting wide open contrast shows.
When I switch to the APO Summicron SL, the rendering on the label is night and day different.
The vertical black bars of the barcode snap with intense, ink black contrast against the stark white backing. There is zero bleed, zero blooming, and zero fringing around the text. You can effortlessly read every tiny, high frequency printed number beneath the UPC bars, and the fine block of text to the left and below separates into clear, legible characters. Beyond the label itself, look at the metal rafter square in the foreground, the stamped numbers and inch markings possess a stark, tactile clarity that immediately draws the eye.
Once again, the APO SL demonstrates what modern, uncompromising optical design can achieve. It renders high contrast, fine detail with surgical precision.
To eliminate any remaining doubt about sensor glass interactions or adapter mounts, I brought both M mount lenses back home to their native habitat, My trusty M11.
To ensure absolute pinpoint focus precision and eliminate any mechanical rangefinder calibration variance, both of these shots were focused using Live View with digital magnification.
The optical contrast between these two lenses on the 60MP M11 sensor is night and day. Lets look into this.
Summilux
In the Summilux file on the M11 seen below, the characteristic wide open veil is unmistakable.
Zooming in on the upper right bristles of the paintbrush, the fine synthetic strands lose their structural definition, dissolving into a soft, hazy glow. The white tips bloom into one another rather than standing out as individual lines. Look at the copper colored ferrule just below the bristles, the stamped numbers and metal grain appear muted, lacking crisp micro contrast. The color rendering and background transition are smooth, However, I believe the lens simply struggles to deliver biting edge sharpness at f/1.4 on the high res sensor that I am looking for.
This is not meant to criticize the lens. I am simply pointing out my persona preference of what I seek as far as rendering goes.
Switching to the APO Lanthar on my M11 reveals a complete, blatant shift in performance.
The difference isn't subtle it snaps into crisp, uncompromising clarity. Punching into the exact same right hand bristles, every single white strand is rendered as a razor sharp, individually separated line with zero optical bloom, zero fringing, and intense micro contrast just as stated in the earlier comparisons above. The stamped text on the ferrule pops with complete, crisp legibility, and the fine texture of the black rubberized handle comes alive.
While the Summilux offers a romantic character wide open, the APO Lanthar proves unequivocally what true apochromatic correction delivers, total, clinical resolving power right at the plane of focus.
Once I stop down to f/5.6, optical math changes the conversation entirely. Wide open aberrations dissolve, depth of field deepens, and even lens designs with soft wide open characteristics clean up across the frame. Shooting these three outdoor scene exposures on their native bodies each taken at f/5.6 serves as the ultimate equalizer test.
At normal viewing distances and web resolutions, discerning the optical differences among these three frames becomes significantly more challenging.
Summilux
Stopped down to f/5.6 on my M11, the Summilux undergoes a complete transformation.
The spherical haze that plagued the wide open portrait and garage shots vanishes completely. Look at the wood grain on the shelter posts and the individual dahlia petals in the surrounding garden beds, edge contrast is sharp, defined, and vibrant. The lens retains its trademark warm color balance and rich micro contrast, proving that its sharpness issues are strictly a wide open f/1.4 phenomenon. When stopped down to medium apertures, it delivers all the crisp, landscape level detail I could ask for. Too bad for me I prefer shooting people, street and street portraits.
On my M11 at f/5.6, the APO Lanthar maintains its surgical clarity from edge to edge.
Because it is already blistering sharp wide open at f/2, stopping down to f/5.6 simply expands the depth of field across the entire flower field and background evergreen trees. The fine vertical lattice work behind the flowers and the texture on the corrugated roof of the structure are rendered with razor like sharpness. Color balance is slightly cooler and more neutral than the Summilux, but resolving power is rock solid across the entire frame.
Shot on the SL system at f/5.6, the APO Summicron-SL matches the APO Lanthar step for step in pure sharpness, while holding onto a slight advantage in overall scene depth.
The clarity across the orange VW bus paintwork, the fine text on the small signs inside the open door, and the pine needles in the background trees is outstanding. The APO SL delivers the same relentless micro contrast and corner to corner resolving power as the Lanthar, but with the slightly richer, punchier Leica color signature seen in the Summilux frame.
When I move out of my controlled close distance setups from my garage and step onto the sidewalk of Main Street in Battle Ground, the visuals shifts once more. At moderate street shooting distances focusing on the potted plant under the awning the differences across all three lenses at f/2 become subtle, requiring a discerning eye to parse out tone, contrast, and depth.
Summilux
With the Summilux shooting wide open at f/1.4, the optical character of the lens becomes crystal clear at medium street distances.
Unlike the close up, close distance garage test where f/1.4 introduced a noticeable spherical haze across fine details, at a typical street shooting distance of 6 to 8 feet, the wide open performance holds up remarkably well on the monstera leaves. The subject remains sharp and legible, but what really defines the frame is the immediate, buttery background isolation. The OOF sidewalk, distant cars, and light fixtures melt into a smooth wash that gives the frame an sense of depth and mood that only a true f/1.4 optic can render.
Taking the shot wide open at f/2, the APO Lanthar trades that wide open f/1.4 background melt for absolute edge contrast and transparency.
Because it is capped at f/2, the background down Main Street remains slightly more structured and legible compared to the Summilux's f/1.4 wash. However, at this subject distance, the difference in total background blur between f/1.4 and f/2 is far less drastic than many would expect. The trade off is pure optical bite, the leaves of the monstera plant and the wood grain on the tables display intense, crisp micro contrast with zero optical aberrations right out to the edges.
I truly believe that shooting wide open at f/2 on the SL system, the APO Summicron SL bridges the gap between the two M mount lenses flawlessly.
It delivers the same ruthless, razor sharp leaf and texture detail as the APO Lanthar at f/2, but its background mechanics roll off far more smoothly. Even at f/2, the background down the covered walkway feels softer and less nervous than the Lanthar's, giving the central plant a striking 3D pop off the glass storefront while maintaining total color and zero chromatic fringing.
If I ever need a definitive case for why the f/1.4 light gathering and aperture design of the Summilux exist, this dahlia garden scene lays it out for me cleanly. In complex outdoor scenes filled with competing background elements, flags, and hard specular reflections across the street, the extra half stop plus of light makes a undeniable difference.
Summilux
This frame is an absolute knockout victory for the Summilux's rendering signature.
At f/1.4, the background completely dissolves into a lush, dreamlike wash. Look directly behind the main dahlia bloom, the distant car reflections and background streetlights transform into large, perfectly soft, circular bokeh orbs. The white picket fence, pink promotional flag, and background buildings melt away effortlessly, keeping my eye entirely locked onto the vibrant orange flower. The character here isn't a defect, it is pure optical magic. It separates subject from context with a soft, cinematic elegance that neither of the f/2 lenses can replicate.
This is why I struggle so much with which 50 to use due to my expectations. Maybe I should just have two M11's one with each lens mounted. 😁
Switching to the APO Lanthar at f/2, the flower itself is rendered with pin sharp clarity, but the background tells a very different story.
Because it lacks that f/1.4 light envelope, the background elements retain significantly more edge definition and structure. The pink espresso flag remains readable, the picket fence holds firm lines, and the background specular highlights shrink into smaller, less dramatic points of light. The image feels much more "busy" overall, forcing the dahlia to compete with the environment for visual attention.
What a dilemma for me. I want the best of both worlds. Maybe time to reshoot this with the Voigtlander 1.0 Nokton to see how it holds up by stopping it down to 1.4.
Once again, APO Summicron SL delivers a remarkably smooth background blur for an f/2 lens, but it still cannot cheat physics against a true f/1.4.
The subject detail on the dahlia petals is staggering, showing incredible color depth and micro contrast. The roll off behind the flower is visibly smoother and less nervous than the APO Lanthar, softening the fence and background building nicely. However, the background highlights and distant street elements simply lack the large, commanding bokeh orbs and dramatic isolation achieved by the Summilux shot wide open.
(Note: Due to the spontaneous nature of grabbing a portrait inside the gas station, there wasn't time to swap onto the APO Lanthar. This head to head focuses strictly on the Summilux M manual focus experience versus the native APO Summicron SL on the SL system).
Both images were taken stopped down to f/2.8, an aperture where depth of field is forgiving enough to hold focus across a subject's facial features while keeping background shelves softly separated.
Summilux
The Summilux frame turned out solid, offering a rich, warm skin tone and a gentle rendering across the subject's face.
At f/2.8, the lens cleans up its wide open softness significantly. Detail around the eyes, mustache, and shirt logo is sharp and present. However, manual rangefinder or EVF focus in a quick candid moment requires concentration, As we all know and have experienced, even a slight sway from either the photographer or subject can push the focal plane off the eye pupil. The background shelving in the Chevron store melts nicely, but the image relies heavily on the my ability to nailing focus manually under pressure. And, I'm not the best at that.
Here, the native SL system delivers a commanding win driven equally by optical perfection and modern usability.
Autofocus Speed & Hit Rate
In a quick, spontaneous interaction where I don't have time to swap lenses or micro adjust manual focus rings, eye detection autofocus locks on instantly. I managed to capture the genuine, unforced expression on the subject's face without the anxiety of missing critical focus.
Note to Leica. Make an EV1 that does AF with M lenses. If Nikon can do it with a third part adapter, you can make it happen natively!
Micro Contrast & Insanely sharp detail
Zooming in on the subject's eyes, skin texture, and stubble, the APO SL delivers extraordinary, tack sharp resolution. The hair strands, eyebrow definition, and tiny specular highlights in the eyes pop with absolute clarity. And all this af only f2.8. This lens simply rules!
The combination of seamless autofocus and uncompromising apochromatic performance makes the APO Summicron SL an unbeatable tool for fast paced street portraiture. The undisputed king! 🤴🤴🤴🤴🤴🤴
Evaluating these flame like red hot pokers (Kniphofia, so says my wife the Gardner) wide open in bright outdoor light reveals how each lens handles punchy, warm hues and micro textures. This set highlights a decisive victor in overall color pop, micro contrast, and tonal depth.
Summilux
The Summilux delivers a smooth look, with wide open f/1.4 rendering creating a soft transition to the background. However, the extreme orange red tones bleed slightly into one another due to spherical glow at f/1.4, softening the delicate structure of the individual tubular petals.
I can see this on the image when I zoom in. Maybe not so much on these uploaded versions. But believe me, it is there.
The APO Lanthar resolves individual flower stems with clinical precision. It eliminates chromatic aberrations, but I feel the overall color rendering feels a bit flatter and slightly muted. Notice the greens in the lawn and the fiery oranges of the blooms lack visual punch, leaning cold rather than vibrant.
The APO-Summicron SL takes the crown👑 in this environment. It captures an extraordinary level of detail without sacrifcing visual excitement. The red orange hues pop off the screen with rich color saturation and intense micro contrast, while preserving the delicate texture of every individual bud on the torch. Combined with a balanced background transition and superior color volume, the SL version produces an unmistakably rich, 3D image that outshines both M mount competitors.
Final thoughts
After evaluating these three exceptional 50mm lenses across macro close ups, street scenes, wide open bokeh, and stopping down to f/5.6, one truth becomes clear, there is no single “perfect” lens for every photographer, but each of these lenses excels when judged against its intended purpose.
The Summilux M remains an iconic lens, offering a fast f/1.4 aperture, warm color signature, and magnificent background bokeh orbs that melt competing background elements into a beautiful creamy wash. However, when shot wide open at close distances, its spherical haze and loss of micro contrast leave something to be desired, especially for a lens carrying a $5,500 premium. It shines brightly for street and environmental portraiture where character and light gathering supersede clinical sharpness, but those seeking absolute wide open perfection in a manual focus 50mm f/1.4 will find that the Zeiss Otus 50mm f/1.4 remains in a league of its own
The APO Lanthar Clinical Value for M-mount shooters who demand absolute optical purity, the Voigtlander is an extraordinary feat of engineering. It delivers razor sharp, corner to corner clarity and total apochromatic correction wide open at f/2. While its color rendition leans cooler and its background rendering can appear slightly more structured and busy than the Leica glass, its performance to price ratio is unbeatable for landscape, architectural, and detailed manual focus work.
The Leica 50mm APO Summicron SL is the undisputed king.🤴🤴🤴🤴🤴 If forced to pick a single winner overall, the APO SL stands alone at the top of the mountain. Regardless of the f/2 versus f/1.4 debate, its combination of lightning fast eye detection autofocus, blistering wide open micro contrast, rich color volume, and smooth background transitions makes it the ultimate 50mm lens available today, delivering an image transparency and 3D depth unmatched by any competitor. It is a hard pill to swallow for rangefinder purists, but even the legendary APO Summicron M nowhere near matches the SL version in sheer optical performance and rendering. In real world shooting, the M mount APO behaves much more like the Voigtlander APO Lanthar, clinical, sharp, and corrected rather than capturing the breathtaking pop of its SL sibling. The only real compromise of the APO SL remains its physical footprint. if Leica ever managed to squeeze its true optical brilliance into the compact form factor of an M lens, the search for the absolute 50mm standard would be officially over. For now, I consider myself fortunate to have all these lenses in my kit, and I am actively trying to put more miles on my SL camera body. It is just remarkably hard to walk away from that pure rangefinder experience.
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On a side note, next week, I will have the Voigtlander 50mm f1.0 Nokton Asph. I will try and replicate some of the images from this review with the lens wide open at f1.0 and stopped down to f1.4 to mimic the Summilux rendering. It will be interesting to see these results. Stay tuned ....
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Looking at this image, the overall atmosphere and color transition are undeniably beautiful. The roll off into the background pillows is silky and gradual, creating a lovely sense of depth. Just what you would expect from the Summilux.
However, when we turn our attention directly to the primary point of critical focus, the eyelashes, the exact issue which concerns me comes into view. The eyelashes are in the focal plane, but they lack that defined, razor sharp edge definition I so desire to see out of a $5500.00 lens. Instead of individual, crisp strands, there is a distinct glow and slight micro contrast drop around the lash line.
Critics might jump to motion blur given that this was shot handheld, but looking closely across the rest of the subject's features like the fine skin texture along the cheek or the strands of hair near the temple there are no double edges or directional trailing indicative of camera movement. The shutter speed was sufficient. What we are seeing is pure wide open optical behavior of the Summilux a characteristic spherical glow and softer micro contrast wide open that blurs the finest structural lines of the lashes, giving them a gentle, dreamy rendering rather than surgical resolution.
The moment you switch to the APO Lanthar frame, the visual narrative changes completely right at the focal point.
Punching directly into the eyelashes, the difference is immediate. The fine, individual lash hair strands snap with razor sharp micro contrast and incredible edge definition. There is ZERO wide open haze or spherical softness here. The optical correction of the APO design renders every single lash cleanly separated, dark, and biting against the skin, revealing exact structural detail.
As for the background, being capped at f/2 versus f/1.4 does mean the background elements retain slightly more structure. Look closely at the dark green and beige cushions behind my daughter, the edges are just a fraction firmer than they were through the Summilux. However, the penalty in blur is nowhere near as drastic as the numbers might suggest on paper. The APO Lanthar's rendering remains smooth and natural, yielding a clean isolation without any distracting harshness or chromatic fringing in the OOF areas.
You lose a tiny slice of that ultra creamy f/1.4 background melt, but in exchange, you get absolute, uncompromising clarity right where your eye lands first.
Summilux
Looking at the Summilux file, the overall color signature and atmosphere are characteristically warm and gentle. The yellow coiled hose and background elements melt away smoothly.
However, inspecting the key target area, the fine bristles on the upper right edge of the brush you can see that familiar spherical glow creeping in again. The individual bristle tips blend together slightly, surrounded by a soft halo rather than sharp separation. The text stamped on the metal ferrule lacks punch, and the overall contrast across the focal plane feels muted. It yields a pleasing, painterly rendering, but since I am looking for distinct, micro detailed separation on fine lines, it falls short of for me. It just doesn't have that modern clinical resolution.
Don't get me wrong. Its a fantastic lens that set a standard and is highly praised. I am just saying, for what I am looking for, it falls a little short.
Switching to the APO Lanthar, once again the jump in structural clarity is immediate. The individual bristles on the right side snap into focus with zero blooming or fringing around the fine white tips.
The micro contrast across the metallic ferrule and black rubberized handle rises dramatically compared to the Summilux. Because it is an f/2 lens, the yellow coiled air hose in the foreground retains slightly more edge structure, but the background highlights remain smooth and well behaved. The APO design does exactly what it promises, it eliminates chromatic aberrations and delivers raw, biting resolving power right at the point of focus.
The APO Summicron SL photo takes everything up a notch. It combines the extreme, surgical contrast of an apochromatic design with an almost three dimensional pop that makes the paintbrush jump off the frame. There is a reason why this lens is considered by many to be the best 50mm ever made.
Zooming into those right hand bristles, the edge definition is staggering. every single strand is rendered with total clarity, rich micro contrast, and zero optical haze. What makes the SL lens so remarkable here is how it manages the OOF areas. Despite being an f/2 lens, the transition from the ultra sharp focal plane into the background roll off feels distinctly smoother and more organic than the APO Lanthar, while matching (if not exceeding) its raw resolving power. It delivers razor precision without ever looking clinical or harsh.
God, I love this lens!
For this set, we shift the critical focus point down to the product label, specifically the UPC barcode and surrounding fine text sitting on the workbench. High contrast black and white lines like a barcode are absolute ruthless indicators of optical resolution, micro contrast, and wide open chromatic behavior.
Summilux
In the Summilux exposure, the overall scene maintains that smooth, gentle character across the foreground square and background tools.
Zooming in on the barcode label, the vertical lines and the small numerical text under the UPC are readable, but they carry a distinct soft edge. The black bars bleed slightly into the white gaps, creating a subtle lower contrast haze across the label. The fine print to the left of the barcode loses its crispness, appearing more like a continuous block of gray text rather than individual, razor sharp letters. It works fine at a distance, but punched in, the lack of biting wide open contrast shows.
When I switch to the APO Summicron SL, the rendering on the label is night and day different.
The vertical black bars of the barcode snap with intense, ink black contrast against the stark white backing. There is zero bleed, zero blooming, and zero fringing around the text. You can effortlessly read every tiny, high frequency printed number beneath the UPC bars, and the fine block of text to the left and below separates into clear, legible characters. Beyond the label itself, look at the metal rafter square in the foreground, the stamped numbers and inch markings possess a stark, tactile clarity that immediately draws the eye.
Once again, the APO SL demonstrates what modern, uncompromising optical design can achieve. It renders high contrast, fine detail with surgical precision.
To ensure absolute pinpoint focus precision and eliminate any mechanical rangefinder calibration variance, both of these shots were focused using Live View with digital magnification.
The optical contrast between these two lenses on the 60MP M11 sensor is night and day. Lets look into this.
Summilux
In the Summilux file on the M11 seen below, the characteristic wide open veil is unmistakable.
Zooming in on the upper right bristles of the paintbrush, the fine synthetic strands lose their structural definition, dissolving into a soft, hazy glow. The white tips bloom into one another rather than standing out as individual lines. Look at the copper colored ferrule just below the bristles, the stamped numbers and metal grain appear muted, lacking crisp micro contrast. The color rendering and background transition are smooth, However, I believe the lens simply struggles to deliver biting edge sharpness at f/1.4 on the high res sensor that I am looking for.
This is not meant to criticize the lens. I am simply pointing out my persona preference of what I seek as far as rendering goes.
Switching to the APO Lanthar on my M11 reveals a complete, blatant shift in performance.
The difference isn't subtle it snaps into crisp, uncompromising clarity. Punching into the exact same right hand bristles, every single white strand is rendered as a razor sharp, individually separated line with zero optical bloom, zero fringing, and intense micro contrast just as stated in the earlier comparisons above. The stamped text on the ferrule pops with complete, crisp legibility, and the fine texture of the black rubberized handle comes alive.
While the Summilux offers a romantic character wide open, the APO Lanthar proves unequivocally what true apochromatic correction delivers, total, clinical resolving power right at the plane of focus.
At normal viewing distances and web resolutions, discerning the optical differences among these three frames becomes significantly more challenging.
Summilux
Stopped down to f/5.6 on my M11, the Summilux undergoes a complete transformation.
The spherical haze that plagued the wide open portrait and garage shots vanishes completely. Look at the wood grain on the shelter posts and the individual dahlia petals in the surrounding garden beds, edge contrast is sharp, defined, and vibrant. The lens retains its trademark warm color balance and rich micro contrast, proving that its sharpness issues are strictly a wide open f/1.4 phenomenon. When stopped down to medium apertures, it delivers all the crisp, landscape level detail I could ask for. Too bad for me I prefer shooting people, street and street portraits.
On my M11 at f/5.6, the APO Lanthar maintains its surgical clarity from edge to edge.
Because it is already blistering sharp wide open at f/2, stopping down to f/5.6 simply expands the depth of field across the entire flower field and background evergreen trees. The fine vertical lattice work behind the flowers and the texture on the corrugated roof of the structure are rendered with razor like sharpness. Color balance is slightly cooler and more neutral than the Summilux, but resolving power is rock solid across the entire frame.
Shot on the SL system at f/5.6, the APO Summicron-SL matches the APO Lanthar step for step in pure sharpness, while holding onto a slight advantage in overall scene depth.
The clarity across the orange VW bus paintwork, the fine text on the small signs inside the open door, and the pine needles in the background trees is outstanding. The APO SL delivers the same relentless micro contrast and corner to corner resolving power as the Lanthar, but with the slightly richer, punchier Leica color signature seen in the Summilux frame.
Summilux
With the Summilux shooting wide open at f/1.4, the optical character of the lens becomes crystal clear at medium street distances.
Unlike the close up, close distance garage test where f/1.4 introduced a noticeable spherical haze across fine details, at a typical street shooting distance of 6 to 8 feet, the wide open performance holds up remarkably well on the monstera leaves. The subject remains sharp and legible, but what really defines the frame is the immediate, buttery background isolation. The OOF sidewalk, distant cars, and light fixtures melt into a smooth wash that gives the frame an sense of depth and mood that only a true f/1.4 optic can render.
Taking the shot wide open at f/2, the APO Lanthar trades that wide open f/1.4 background melt for absolute edge contrast and transparency.
Because it is capped at f/2, the background down Main Street remains slightly more structured and legible compared to the Summilux's f/1.4 wash. However, at this subject distance, the difference in total background blur between f/1.4 and f/2 is far less drastic than many would expect. The trade off is pure optical bite, the leaves of the monstera plant and the wood grain on the tables display intense, crisp micro contrast with zero optical aberrations right out to the edges.
Well done Cosina!
I truly believe that shooting wide open at f/2 on the SL system, the APO Summicron SL bridges the gap between the two M mount lenses flawlessly.
It delivers the same ruthless, razor sharp leaf and texture detail as the APO Lanthar at f/2, but its background mechanics roll off far more smoothly. Even at f/2, the background down the covered walkway feels softer and less nervous than the Lanthar's, giving the central plant a striking 3D pop off the glass storefront while maintaining total color and zero chromatic fringing.
Summilux
This frame is an absolute knockout victory for the Summilux's rendering signature.
At f/1.4, the background completely dissolves into a lush, dreamlike wash. Look directly behind the main dahlia bloom, the distant car reflections and background streetlights transform into large, perfectly soft, circular bokeh orbs. The white picket fence, pink promotional flag, and background buildings melt away effortlessly, keeping my eye entirely locked onto the vibrant orange flower. The character here isn't a defect, it is pure optical magic. It separates subject from context with a soft, cinematic elegance that neither of the f/2 lenses can replicate.
This is why I struggle so much with which 50 to use due to my expectations. Maybe I should just have two M11's one with each lens mounted. 😁
Switching to the APO Lanthar at f/2, the flower itself is rendered with pin sharp clarity, but the background tells a very different story.
Because it lacks that f/1.4 light envelope, the background elements retain significantly more edge definition and structure. The pink espresso flag remains readable, the picket fence holds firm lines, and the background specular highlights shrink into smaller, less dramatic points of light. The image feels much more "busy" overall, forcing the dahlia to compete with the environment for visual attention.
What a dilemma for me. I want the best of both worlds. Maybe time to reshoot this with the Voigtlander 1.0 Nokton to see how it holds up by stopping it down to 1.4.
Once again, APO Summicron SL delivers a remarkably smooth background blur for an f/2 lens, but it still cannot cheat physics against a true f/1.4.
The subject detail on the dahlia petals is staggering, showing incredible color depth and micro contrast. The roll off behind the flower is visibly smoother and less nervous than the APO Lanthar, softening the fence and background building nicely. However, the background highlights and distant street elements simply lack the large, commanding bokeh orbs and dramatic isolation achieved by the Summilux shot wide open.
Both images were taken stopped down to f/2.8, an aperture where depth of field is forgiving enough to hold focus across a subject's facial features while keeping background shelves softly separated.
Summilux
The Summilux frame turned out solid, offering a rich, warm skin tone and a gentle rendering across the subject's face.
At f/2.8, the lens cleans up its wide open softness significantly. Detail around the eyes, mustache, and shirt logo is sharp and present. However, manual rangefinder or EVF focus in a quick candid moment requires concentration, As we all know and have experienced, even a slight sway from either the photographer or subject can push the focal plane off the eye pupil. The background shelving in the Chevron store melts nicely, but the image relies heavily on the my ability to nailing focus manually under pressure. And, I'm not the best at that.
Here, the native SL system delivers a commanding win driven equally by optical perfection and modern usability.
Autofocus Speed & Hit Rate
In a quick, spontaneous interaction where I don't have time to swap lenses or micro adjust manual focus rings, eye detection autofocus locks on instantly. I managed to capture the genuine, unforced expression on the subject's face without the anxiety of missing critical focus.
Note to Leica. Make an EV1 that does AF with M lenses. If Nikon can do it with a third part adapter, you can make it happen natively!
Micro Contrast & Insanely sharp detail
Zooming in on the subject's eyes, skin texture, and stubble, the APO SL delivers extraordinary, tack sharp resolution. The hair strands, eyebrow definition, and tiny specular highlights in the eyes pop with absolute clarity. And all this af only f2.8. This lens simply rules!
The combination of seamless autofocus and uncompromising apochromatic performance makes the APO Summicron SL an unbeatable tool for fast paced street portraiture. The undisputed king! 🤴🤴🤴🤴🤴🤴
Summilux
The Summilux delivers a smooth look, with wide open f/1.4 rendering creating a soft transition to the background. However, the extreme orange red tones bleed slightly into one another due to spherical glow at f/1.4, softening the delicate structure of the individual tubular petals.
I can see this on the image when I zoom in. Maybe not so much on these uploaded versions. But believe me, it is there.
The APO Lanthar resolves individual flower stems with clinical precision. It eliminates chromatic aberrations, but I feel the overall color rendering feels a bit flatter and slightly muted. Notice the greens in the lawn and the fiery oranges of the blooms lack visual punch, leaning cold rather than vibrant.
The APO-Summicron SL takes the crown👑 in this environment. It captures an extraordinary level of detail without sacrifcing visual excitement. The red orange hues pop off the screen with rich color saturation and intense micro contrast, while preserving the delicate texture of every individual bud on the torch. Combined with a balanced background transition and superior color volume, the SL version produces an unmistakably rich, 3D image that outshines both M mount competitors.
Final thoughts
After evaluating these three exceptional 50mm lenses across macro close ups, street scenes, wide open bokeh, and stopping down to f/5.6, one truth becomes clear, there is no single “perfect” lens for every photographer, but each of these lenses excels when judged against its intended purpose.
The Summilux M remains an iconic lens, offering a fast f/1.4 aperture, warm color signature, and magnificent background bokeh orbs that melt competing background elements into a beautiful creamy wash. However, when shot wide open at close distances, its spherical haze and loss of micro contrast leave something to be desired, especially for a lens carrying a $5,500 premium. It shines brightly for street and environmental portraiture where character and light gathering supersede clinical sharpness, but those seeking absolute wide open perfection in a manual focus 50mm f/1.4 will find that the Zeiss Otus 50mm f/1.4 remains in a league of its own
The APO Lanthar Clinical Value for M-mount shooters who demand absolute optical purity, the Voigtlander is an extraordinary feat of engineering. It delivers razor sharp, corner to corner clarity and total apochromatic correction wide open at f/2. While its color rendition leans cooler and its background rendering can appear slightly more structured and busy than the Leica glass, its performance to price ratio is unbeatable for landscape, architectural, and detailed manual focus work.
The Leica 50mm APO Summicron SL is the undisputed king.🤴🤴🤴🤴🤴 If forced to pick a single winner overall, the APO SL stands alone at the top of the mountain. Regardless of the f/2 versus f/1.4 debate, its combination of lightning fast eye detection autofocus, blistering wide open micro contrast, rich color volume, and smooth background transitions makes it the ultimate 50mm lens available today, delivering an image transparency and 3D depth unmatched by any competitor. It is a hard pill to swallow for rangefinder purists, but even the legendary APO Summicron M nowhere near matches the SL version in sheer optical performance and rendering. In real world shooting, the M mount APO behaves much more like the Voigtlander APO Lanthar, clinical, sharp, and corrected rather than capturing the breathtaking pop of its SL sibling. The only real compromise of the APO SL remains its physical footprint. if Leica ever managed to squeeze its true optical brilliance into the compact form factor of an M lens, the search for the absolute 50mm standard would be officially over. For now, I consider myself fortunate to have all these lenses in my kit, and I am actively trying to put more miles on my SL camera body. It is just remarkably hard to walk away from that pure rangefinder experience.
Chime in below and let me know what you think.