2024 Leica Summilux-SL 50mm F1.4 ASPH review – Setting the benchmark.

Introduction

Announced as the first prime lens in the Leica SL system and available since 2017, the Leica Summilux-SL 50mm ƒ1.4 ASPH has intrigued me for a while not only as the fastest (largest aperture) lens in the Leica SL system but also prompting in me the question of does the performance of this lens match its hefty status. Let us take a deeper look.

*for brevity’s sake, I will now refer to the Leica Summilux-SL 50mm ƒ1.4 ASPH as the Leica SL 50mm ƒ1.4 ASPH. The review was done with the Leica SL2 running firmware version 6.00.

tl:dr

For the first prime lens in the Leica SL system, the Leica Summilux-SL 50mm ƒ1.4 ASPH sets the bar high with an extraordinary build quality and impressive optical performance to match.

The sole drawback I can think of is the sheer weight and bulkiness of this piece of optics, but for the person who seeks the absolute fastest lens in the Leica SL system, the Leica Summilux-SL 50mm ƒ1.4 ASPH as a no-compromise lens design will not disappoint you in any aspect.

Technicalities

The Leica SL 50mm ƒ1.4 ASPH has an advanced modern optical design, comprised of eleven elements arranged in nine groups, with two aspherical lenses and four made from glasses with anomalous partial dispersion to correct chromatic aberrations.

According to Leica, “this complex optical construction reduces all monochromatic and chromatic aberrations to a hardly perceptible minimum,“ which is pretty accurate from my experience with this lens.

• Focal length of 50mm, with an angle of view (diagonal, horizontal, vertical) at 47.9°/40.5°/27.7°
• Aperture range of ƒ1.4 to ƒ22
• Working range of 60 cm to infinity
• An 11 elements in 9 groups optical design with 2 aspherical surfaces
• Filter size of 82mm, at 1065 grams and Length 124mm x 88 mm at widest
• Autofocusing lens, Leica L-mount
• Weather-sealed

Build, handling, and performance

We will discuss the Leica SL 50mm ƒ1.4 ASPH across these three areas that matter to the practical user.

I suspect that when Leica designers were working on the Leica SL 50mm ƒ1.4 ASPH as the first prime lens for the SL System, a decision was made to have this piece of optics set the standard for what is currently possible in lens design with lesser regard for its weight/size.

 

Build-wise, the Leica SL 50mm ƒ1.4 ASPH is built like an M1 Abram’s battle tank, ready to crush anything in its path, including your foot. Holding the lens, I know deep inside that if I do accidentally drop this system onto the ground, it is more likely that the floor tile will need to be replaced, while the SL and lens setup will shrug the impact off with a dent. 

Leica lenses have always been at the top in terms of build quality, and the Leica SL 50mm ƒ1.4 ASPH is clearly no exception, and in in opinion, over-built. Tolerances are tight, and the machining is top-notch, leaving nothing except its weight for anyone to make a fuss about.

The sheer solidness and use of quality materials in the Leica SL 50mm ƒ1.4 ASPH is a level we hardly see nowadays, probably only matched by camera makers like Phase One and Hasselblad, and not a standard we often see anymore.

For a primarily Leica M system user, I do find the Leica SL 50mm ƒ1.4 ASPH huge even without the lens hood mounted, and humongous with the hood mounted, and this is me being plain honest as I guess Leica probably wouldn’t like to read a reviewer associating their equipment with such descriptions.

However I do realise that the sheer performance of the Leica SL 50mm ƒ1.4 ASPH easily outweighs the len’s weight.

Being the Leica SL system, autofocus is an area of consideration. Auto-focusing performance on the Leica SL2 is reliable and, while not going to win any awards for speed, is reasonably fast.

Thanks to the internal focusing design of the Leica SL 50mm ƒ1.4 ASPH, the operation is near silent, and even with the extremely thin depth of field of this piece of optics, the focus reliability is there. For me, internal focusing designs are also important in the durability of the lens, keeping lesser parts exposed to the elements.

Credit to Leica for improving the functionality of the Leica SL2’s autofocus system through firmware updates since 2019. Having tested the Leica Q3 (review here) in June last year, I am sure this lens on the Leica SL3 will deliver even better autofocus performance.

I can confidently say that while the just released Leica SL3 provides a more responsive and reliable autofocusing performance, the Leica SL2 is still capable for most use cases.

Look forward to my review of the Leica SL3 later.

Timing wise, the SL Summilux 50mm ASPH review did not manage to coincide with the SL3’s.

Touching on the third area, the image quality from the Leica SL 50mm ƒ1.4 ASPH is phenomenal, with edge-to-edge sharpness even wide open at ƒ1.4. There is very slight vignetting, which clears up by ƒ2 onwards and can be easily corrected in post-processing. In my opinion, a subtle vignette can be pleasant at times.

In fact, one thing that stood out the most was that whether wide open, stopped down, close-up, or at infinity, the Leica SL 50mm ƒ1.4 ASPH’s output is impressively sharp and crisp, reproducing even the tiniest and finest details well.

The Leica SL-Summilux 50mm ƒ1.4 ASPH was designed to be a no-compromise lens optically.

Chromatic aberrations are well-controlled despite the lens not holding an APO tag, with very pleasant bokeh, which is more modern in its drawing, unlike the gentler/softer look that we find on the Leica M-mount Summilux 50mm ƒ1.4 ASPH or the Noctilux 50mm ƒ0.95. (my reviews are linked)

Conclusions

The Leica Summilux-SL 50mm ƒ1.4 ASPH is an extraordinary lens, not only because it is the fastest (aperture-wise, not A.F speed) lens in the Leica SL system but for its excellent optical performance across the areas that matter. Leica set out to make a benchmark lens for their first SL system prime lens and has managed to set a very high bar.

Combining the sharpness and crispness with the quality bokeh with a lovely realistic color rendition, one has the makings of an incredible lens.

Of course, the size and weight and maybe not as speedy auto-focus versus other interchangeable lens systems will always be a factor, but for the photographers who seek image quality and a fast aperture within the Leica SL-system, the Leica Summilux-SL 50mm ƒ1.4 ASPH is the choice where it is not likely any equal exists and this lens will make a great addition to anyone’s Leica SL kit.

Thank you for reading.

Disclaimers:

1. All product photos and samples here were photographed by me. I believe any reviewer with pride should produce their own product photos. 

2. All images were shot with my personal copies of the Leica SL2 (running firmware 6.0) and the SL-Summilux 50mm ASPH loaned for review purposes.

3. This review is not sponsored. I do not do affiliate links.

4. I write as a passion and a hobby, and I appreciate that photography brands are kind enough to respect and work with me.

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