• – Extraordinary electronic viewfinder
  • – Excellent image quality
  • – Internal 4K video recording
  • – Large, heavy body
  • – Unintuitive controls with poor default set-up
  • – Limited native lens range


  • 24-million-pixel full-frame CMOS sensor
  • ISO 50-50,000
  • 4.4-million-dot ‘EyeRes’ EVF
  • Leica L mount
  • 11fps continuous shooting
  • 4K video at 30fps

There’s something about Leica that makes many photographers go slightly weak at the knees. It’s a name that’s indelibly associated with some of the greatest photographers of all time, including the likes of Annie Leibovitz, Robert Frank, and Henri Cartier-Bresson. The company’s most iconic product line, its M-series rangefinders, is more than 60 years old, and took the seismic transition from film to digital in its stride while barely changing in design. Indeed, the current Leica M-P looks more or less the same as the 1954 M-3, while the Leica M-A is just about the last ‘serious’ 35mm film camera still available.

With all this nostalgia as a distraction, it can be easy to overlook another side of Leica that’s emerged in recent years – that of a company aiming to provide unique tools for professional photographers (or perhaps ambitious enthusiasts with very accommodating bank managers). First were the S-series medium-format DSLRs, based around a 45x30mm Pro Format sensor, and now the company’s SL (Typ 601) full-frame compact system camera.

Front of the Leica SL (Typ 601)

Leica is only the second company to bring out a mirrorless model with a full-frame sensor, after Sony’s groundbreaking Alpha 7 series, although logic dictates that it certainly won’t be the last. The SL stretches the word ‘compact’ in the CSC acronym to breaking point, being as large and as heavy as the average full-frame DSLR. But it’s also a heavyweight in terms of features, being blessed with 11 frames per second continuous shooting, internal 4K video recording and an extraordinary 4.4-million-dot electronic viewfinder, which is easily the best we’ve yet seen on a stills camera.

All this cutting-edge technology might seem alien for Leica, and we rather suspect that the company has spent a lot of time recently picking the brains of its long-time collaborator Panasonic. But no matter where all this know-how comes from, one thing is clear – the SL is a serious proposition. Let’s take a closer look at what it offers.


Usually the first thing we examine with any camera is the sensor, and Leica has opted for a 24-million-pixel full-frame CMOS unit. This does without an optical low-pass filter to maximise acuity, but clearly the SL is still some way behind the latest high-resolution models such as the 50.6MP Canon EOS 5DS R, 42.4MP Sony Alpha 7R II or 36MP Nikon D810. However, Leica is keen to stress that pixel count isn’t the be-all and end-all of image quality, and that the excellence of its lenses should at least partially close the gap. It’s also probably worth pointing out that 24MP is easily sufficient to give highly detailed 24x16in/A2 prints, although higher pixel counts do offer more scope for cropping.


Paired with Leica’s Maestro II image processor, the sensor delivers a standard sensitivity range of ISO 50-50,000. Raw files are recorded as 14-bit DNGs for maximal tonal gradation and easy processing. Continuous shooting is available at a hugely impressive 11 frames per second, with focus and exposure fixed at the start of the burst, dropping to 7fps with live view, autofocus and autoexposure adjustment between frames. Buffering is very respectable, with up to 30 raw frames or 70 JPEGs recordable before the camera starts to slow down.


The sensor sits behind the L-mount, which is physically the same as that used in the Leica T. It’s an all-electronic, four-pronged bayonet, which Leica says was designed with full frame in mind from the start. It’s noticeably larger in diameter than the Sony E-mount used by the Alpha 7 series, giving more space around the full-frame sensor, especially at its corners.

Timed shutter speeds range from 60secs-1/8000sec, with up to 30 minutes available in bulb mode, and a very respectable flash sync of 1/250sec. The shutter is pretty quiet, and the combination of 1/8000sec shutter and ISO 50 allows for shooting at large apertures in bright light. Dual SD card slots are used for storage, and the camera can either record files in duplicate to both cards simultaneously, or switch to using the second when the first is full. Unusually, one slot accepts UHS-II cards, which have a second set of pins for dramatically faster write speeds. This is worth knowing as it can take nearly 90secs to write a full burst of raw files to a conventional SDHC card.


Leica has included an intelligent Auto ISO function that allows you either to set a fixed minimum shutter speed, or specify that this should adjust to match the focal length of the lens in use. Auto ISO can also be used in manual-exposure mode, allowing you to choose the shutter speed and aperture to suit the subject and let the camera adjust the ISO to compensate for changing light; this can be combined with exposure compensation to adjust the image brightness. One neat touch is Floating ISO, where the camera will adjust the ISO purely to compensate for any change in maximum aperture on zooming the lens when shooting wide open.

Aside from the basics, though, the SL has few additional options. There are programmable intervalometer and autobracketing modes, with the latter including the ability to make a high dynamic range JPEG file in-camera. But there’s no space for such fripperies as art filters, panoramic shooting or a multiple-exposure mode. With this in mind, it may come as a surprise to find both Wi-Fi and GPS built in, but Leica considers both to be genuinely useful tools for serious photographers – and I agree.

Where the SL gets particularly interesting, though, is with regards to video recording; it can record 4K video at 30fps using a Super-35 crop of the sensor. As this is a similar area to APS-C, it will work with lenses designed for the Leica T, allowing true wideangle shooting. The camera allows 4K footage to be recorded internally to SD cards in 4:2:0 8-bit mode, or to an external recorder over HDMI in 4:2:2 10-bit mode. Alternatively, full HD video can be recorded at up to 120fps. A dedicated live view mode shows a 16:9 cropped view, with optional focus peaking and zebra-pattern overexposure-warning displays. Slightly disappointingly, though, microphone or headphone sockets can only be added via an adapter that plugs into the camera’s proprietary multi-connector socket.



If there’s one thing Leica really has got absolutely right with the SL, it’s the viewfinder. Its 4.4-million-dot EyeRes finder gives exceptional detail, and a larger view than the optical finders on even top-of-the-range full-frame DSLRs. Its 60fps refresh rate means there’s barely any lag, either. In addition to this, it can display a wide range of exposure information, overlay your choice of gridlines and even display electronic levels. The net result isn’t just the most impressive electronic viewfinder yet, but it’s probably the finest viewfinder on any full-frame camera to date, surpassing even the best optical finders such as that on the Canon EOS 5DS R.

The EVF is backed up by a 3in, 1.04-million-dot rear screen that also gives a bright, detailed view. It’s touch-sensitive, which means it can be used to select the focus point and change certain settings, including ISO and exposure compensation. An eye sensor allows the camera to switch seamlessly between the two viewing methods during shooting. It’s just a pity that the LCD isn’t articulated in any way, which is a disadvantage compared to the tilting screen on the Sony Alpha 7R II.


There’s no getting away from the fact that the SL is a big, heavy camera, especially with its SL 24-90mm f/2.8-4 lens attached. Indeed, it’s as large as full-frame DSLRs such as the Nikon D810 or Canon EOS 5DS R fitted with their 24-70mm f/2.8 zooms. Its build quality appears faultless – the dust and splash-resistant body is machined from two solid blocks of aluminium alloy, and feels totally rigid in your hand. It should shrug off the abuse of daily professional use with ease.


Its matt-black paint finish, square edges, cross-hatched rubberised coating and minimalist controls all combine to give the SL a unique, and very modern, look. I suspect as many people will hate the design as love it, but there’s certainly no risk of it being mistaken for an identikit DSLR. Personally, though, I find the chunky handgrip to be less comfortable than the more sculpted grips on its competitors.

Handling is also decidedly unconventional. Where the aforementioned DSLRs are festooned with buttons and dials to give direct access to every imaginable setting, Leica has adopted a pared-down, minimalist approach that makes do with two dials, a joystick controller and just nine buttons (including the shutter). Apart from the shutter release and video start/stop control, the buttons are all dual function; tapping them does one thing, but holding them briefly down does another. These second functions are all user-customisable, but you have to memorise what each is set to, as the buttons are completely unmarked. It’s a scheme borrowed from the S-series DSLRs that Leica says is well liked by its users. However, I do wonder how many other potential buyers it will put off.

The top dial controls the shutter speed, while the rear dial sets the aperture; clicking the latter inwards and spinning it switches through the usual quartet of exposure modes (program, aperture priority, shutter priority and manual). The multi-controller joystick on the camera’s back is used to move the focus area around the frame; pushing it inwards activates AF, even when the camera is set to manual focus, which can be handy for quickly acquiring focus.

A top-plate button with a red dot in its centre is dedicated to starting and stopping video recording, while the silver button beside it switches the camera between stills and video modes. Unusually, in video mode you can’t shoot stills at all, leaving the shutter button completely unresponsive.


On the front plate are two buttons – one to release the lens and another that cycles through various preview modes. It’s possible to view the image at a standard brightness to give an SLR-like experience, or apply exposure simulation to pre-visualise the effects of your settings. Alongside conventional depth of field preview there’s also a Panasonic-like shutter-speed-simulation option. Anyone coming to the camera for the first time, though, is likely to find themselves trying to release the lens by pushing the preview button, and vice versa, as their respective physical designs are rather counterintuitive.

Perhaps the biggest problem with the SL, though, is that while the buttons are arranged very stylishly around the camera body, only a few are easy to press with the camera to your eye. This is compounded by a poor default set-up that conspicuously fails to assign the most used functions to the most accessible buttons. Exposure compensation is assigned to the left-side button behind the top dial, and ISO to the button top-left of the LCD; both are unreachable without a significant change of grip. However, I re-assigned these settings to the two buttons on the right side of the screen, which are both easily reached by your right thumb, and found that when set up like this the SL worked well.

Unusually, I didn’t find the touchscreen to be very useful while shooting, mainly because I was working with the EVF all the time and only a few shooting settings have been given a touch interface anyway. The screen can at least be used to browse through images in playback, although it isn’t as responsive with this as it could be.



Leica has made very bold claims about the SL’s autofocus, saying it’s the world’s fastest in any full-frame camera, and while this should be taken with a pinch of salt I had few complaints in real-world use. In fact, the autofocus behaves much as I’d expect from a modern contrast-detection system; it’s very fast, essentially silent and near 100% accurate. It also works well in low light, so long as you pay attention to where you place the focus area (which is made very easy by the SL’s joystick controller).

Manual focusing is a breeze, too, due to the huge clear viewfinder and optional focus-peaking display. For the most accurate focusing, live-view magnification can also be engaged in two steps, by tapping the button lower left of the LCD. This is a bit awkward when shooting with the heavy 24-90mm kit zoom, but it should be less of a problem for those using manual-focus lenses via a mount adapter.


In practical use, the SL performs very well. With no anti-aliasing filter, the sensor is capable of recording loads of detail, and its impressive noise performance means that sensitivities up to ISO 12,500 are quite usable. Metering tends to be accurate, and it’s easy to preview the effects of your exposure settings in the viewfinder and apply any necessary changes before even taking a shot.


I was a little disappointed by the camera’s JPEG output, which gives muted colours and white balance that errs to the cool side. To be fair, though, I’d expect almost everyone using this camera to be shooting raw, and the DNG output means you can get to work straight away with the software of your choice. Indeed, the raw files are impressively malleable, with lots of scope for pulling detail from deep shadows at low ISOs.

Currently, the Vario-Elmarit-SL 24-90mm f/2.8-4 Asph is the only autofocus full-frame lens that can be used on the SL, and will therefore be a major determinant of its image quality for most early adopters. Fortunately, it’s exceptional, as we’d expect given its price tag. It’s superbly sharp, with minimal chromatic aberration or vignetting.

Close examination of raw files shows that Leica has adopted a thoroughly modern approach of allowing more barrel distortion at wideangle than would be acceptable from a DSLR lens and compensating automatically in software, which allows other image-degrading aberrations to be corrected more thoroughly. The result is a lens that’s as sharp wide open as it is stopped down to f/8, no matter what focal length you use. The zoom range also extends very usefully into the short telephoto ‘portrait’ realm, where conventional 24-70mm zooms come up a little short.




Leica has fitted the SL with a 24-million-pixel full-frame CMOS sensor, which it says is related to that inside the Leica Q (Typ 116) full-frame compact, and is not the Sony unit used in several other full-frame cameras. Specifically, the design of its pixels means that they can accept incoming light from more acute angles, which according to Leica means it should be less prone to the colour shading and corner smearing that can be seen when shooting with certain M-mount wideangle lenses.

With no low-pass filter, the sensor resolves a lot of detail, although this means it can occasionally be prone to giving image artefacts in return. As we’d expect from a modern full-frame sensor, low ISO dynamic range is very high, and high ISO noise performance very commendable, too.


At low ISOs of 50-200, the SL gives an impressively high dynamic range of 12.5EV or more in our Applied Imaging tests, indicating that raw files should offer significant scope for manipulation and recovering shadow detail in particular. Beyond ISO 400, it starts to fall more rapidly, and by the time we get beyond ISO 3,200 it’s rather low, indicating that at this point noise will start to have a more serious impact on detail. At ISOs 25,000 and 50,000 we see very low readings, suggesting these settings should be avoided.



With a measured resolution at ISO 50 of almost 4,000l/ph, the SL gets about as much out of its 24-million-pixel sensor as theoretically possible. This also confirms that the 24-90mm zoom is impressively sharp; we shot these tests at 50mm and f/5.6. Stepping up through the ISO range sees resolution slowly diminish due to the effects of noise, but it’s still around 3,600l/ph at ISO 1,600, and 3,400l/ph at ISO 6,400. Beyond this, things take a turn for the worse, with noise limiting resolution to 2,800l/ph at the highest setting.








Both raw and JPEG images taken from our diorama scene are captured at the full range of ISO settings. The camera is placed in its default setting for JPEG images. Raw images are sharpened and noise reduction applied, to strike the best balance between resolution and noise.







With beautifully clean and detailed images, the Leica SL gives excellent results at low ISO settings. In normally processed images, it maintains near-indistinguishable image quality at ISO 1,600, with just a little noise creeping into shadow regions if you examine images very closely at the pixel level. ISO 3,200, however, is still very good indeed, and it’s only at ISO 6,400 that fine details start to get visibly blurred by the impact of noise. Step up to ISO 12,500, though, and things start to deteriorate more quickly; low-frequency colour botching is detectable in shadow regions, and fine low-contrast detail is beginning to get overwhelmed by noise. Even so, this setting should be acceptable for small prints or web use. The top two sensitivities, in contrast, really aren’t very good at all, and should be reserved for situations where there’s no other option.



From the moment you set eyes on the Leica SL, it’s clear this is no ordinary camera. With its slab-sided design and minimalist unmarked controls it looks like nothing else on the market, particularly when kitted with its huge 24-90mm zoom. The spec sheet is impressive, too; no other full-frame camera has quite the same combination of resolution and speed.

There’s little to complain about in terms of image quality, either, with the sensor and lens combining to deliver superb results. The addition of 4K video shooting is the icing on the cake.

Unfortunately, though, the SL’s eccentric control system with its unmarked, dual-function buttons marks it out as one of the least intuitive cameras to pick up and use that we’ve seen for a long time. Indeed, it’s almost the antithesis of Leica’s other recent design, the rangefinder-like Q, with its traditional control dials. But after spending some time studying it and reconfiguring it to my liking,

I enjoyed shooting with the SL more than I initially expected. This is mainly down to its fabulous viewfinder, with its huge, bright and detailed view, and ability to preview more or less exactly how your image will look before shooting. This is surely the future, and once you’ve experienced the benefits of looking at the world through an EVF this good, you may find yourself reluctant to ever go back to using a DSLR.

But despite all its clever technology, does the Leica SL really make sense at the moment, particularly compared to the less expensive full-frame alternatives from Canon, Nikon or Sony, which also have many more lenses to choose from? For the majority of photographers, probably not, but in a way that’s the point. Leica isn’t really trying to be a mainstream player anyway; instead, it’s made a very intriguing – and capable – camera that will suit a minority of photographers very well indeed.

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