Fujifilm GFX 50S VS Nikon D850

It’s the test we’ve all been waiting for: the ultimate clash of the titans, as we pitch the awesome Fujifilm GFX 50S against the mighty Nikon D850…

In the past, full-frame DSLRs and medium-format digital cameras were separated by a huge gulf. Medium-format cameras were huge and unwieldy and ruinously expensive, but delivered a level of resolution completely beyond the reach of full-frame DSLRs.

But two things have happened. First, full-frame DSLR resolution has leapt up to match that of many medium-format cameras; and then the slimmed-down Fujifilm GFX 50S and Hasselblad X1D arrived at a size and price much closer to those of a full-frame DSLR.

We’ve lined up the brand new Nikon D850 to represent the latest state-ofthe-art tech in full-frame DSLRs, and the mirrorless Fujifilm GFX 50S, the medium-format camera which perhaps gives the most recognisable shooting experience for those upgrading from a smaller format.

Both cameras capture more or less 50 million pixels, so the image quality comparisons will prove very interesting, but in practically every other respect they are completely different to use. ‘Chalk and cheese’ hardly covers it!

The cameras’ sensors also take very different approaches. The GFX has 51.4 megapixels versus the 45.7 megapixels of the D850, but that’s not as significant as the size difference. The GFX’s sensor measures 43.8 x 32.9mm compared with the D850’s 35.9 x 23.9mm.

There’s a difference in the aspect ratios, too. The D850 has the 3:2 aspect ratio of other full-frame DSLRs (and cameras with APS-C sensors), but the GFX has a squarer 4:3 ratio. Horizontalformat shots will look a little less wide, but vertical shots tend to look a little more natural at this ratio.

We tend to think of medium-format as being much larger than 35mm fullframe, but digital medium-format sensors come in two main sizes, and the GFX 50S’s is the smaller size – you could say it’s the APS-C equivalent of the medium-format world.

So although it is larger than the D850’s sensor, it’s not a massive step up. It’s about 68% greater in area. It should yield an improvement in image quality, then, but it’s not like stepping up to a ‘full-size’ medium-format sensor, which is close to the old 6 x 4.5cm film format.

The viewing systems of these two cameras are examined in more depth in the build and handling section, but the main difference here is that the D850 is a DSLR with a mirror, a pentaprism and an optical viewfinder, while the GFX is a mirrorless camera which uses the main sensor to supply a live digital feed to either its electronic viewfinder or its rear screen.

The D850 and GFX use two very different sets of autofocus technologies, reflecting these two cameras’ very different strengths. The GFX uses a relatively straightforward contrast autofocus system; you would not expect this to be fast, but it is both precise and versatile, with Single Point, Zone and Wide/Tracking modes. It uses 425 autofocus points occupying most of the image area and used (depending on the mode) in customisable clusters.

The D850’s approach is different. For regular viewfinder shooting, it uses Nikon’s latest and best Multi-Cam 20K phase-detection autofocus sensor, with 153 AF points – 55 of which are userselectable and 99 of which are more accurate cross-type sensors. It’s the same system used in Nikon’s high-speed D5 and D500 cameras, and is used here to provide the same kind of high-speed focus acquisition and subject tracking capabilities you get from those models.

In practically every respect they are completely different to use. ‘Chalk and cheese’ hardly covers it!

In Live View mode, the D850 has to swap to its sensor-based contrast AF system, which levels up the playing field considerably. Here, the D850 is a similar proposition to the GFX, though it carries over its high-speed capabilities with its 6fps silent mode.

The biggest differences between these two cameras show up in their continuous shooting performance. The GFX can lumber along at 3fps; but the D850 can hit 7fps in regular viewfinder shooting, an incredible 9fps with the optional battery grips fitted, and 6fps at full resolution in silent Live View mode (or 30fps for 8-megapixel images). The GFX is not really designed for action photography, but the D850 is – and it’s so good at it, that it even challenges sports specialists like the Nikon D5 and D500.

There are differences in these two cameras’ movie capabilities too. Fujifilm is keen to play up the ‘cinematic’ look of video shot with the GFX’s big sensor and fast(ish) prime lenses, but it only shoots full HD video at 1920 x 1080 pixels, and at a maximum frame rate of 30fps. The Nikon D850, however, shoots UHD 4K at up to 30fps and full HD at up to 60fps. It too can boast a ‘cinematic’ look because it uses the full sensor width for 4K video and has access to a large range of fast Nikon prime lenses.

We always say you should judge a camera’s lens system, not just the camera, and at first glance this does seem a one-sided battle. It’s traditional for medium-format lens systems to be somewhat restricted, and so far the GFX has just six lens options, from the GF23mm F4 R LM WR (18mm equivalent, actually rather impressive) up to the GF120mmF4 R LM OIS WR Macro. There’s only one zoom in the range, the GF32-64mm F4 R LM WR. If the continuous shooting speed and autofocus system didn’t rule out the GFX for long-range sports photography, the limited lens range would. It’s just not that kind of camera.

There are practical differences too. The GFX and D850 both offer dual memory card slots; but where the GFX takes two SD/SDHC/SDXC cards (it is UHS-II compatible), the Nikon has one XQD card slot and one UHS-II compatible SD/SDHC/SDXC slot – and you need a super-fast XQD card to achieve Nikon’s quoted raw buffer capacity of 51 14-bit raw files.

Then there’s the battery life. The GFX will exhaust its chunky battery in about 400 shots, while the D850 can capture up to 1,840 on a single charge – although this will fall if the Nikon is used extensively in Live View mode.

Build and handling

Fujifilm describes the GFX 50S as “compact and lightweight”, and from the front the GFX looks like an upscaled version of Fujifilm’s X-T2 and no more bulky than a DSLR. Round the back, though, the housing for the tilting LCD screen protrudes some distance from the back of the camera, and makes it feel pretty bulky in your hands. Once you’ve added a lens, the GFX feels noticeably

bigger than the D850. Both cameras use a magnesium alloy chassis for robustness, and both are fitted with weather-resistant seals. Fujifilm’s GF lenses are weather-resistant too, as are many (but not all) Nikon lenses.

The control layouts are completely different. The GFX uses old-style external exposure controls, with a shutter speed dial on the top plate, aperture rings on the lenses and an external ISO dial. There’s no mode dial because different combinations of auto and manual settings on the shutter speed and aperture controls produce the regular PASM exposure mode options.

The unusual shape of the GFX means that some of the buttons are in unusual places too – the playback button and focus mode levers, for example, are on the top edge of the LCD display housing.

The D850 has no mode dial either, but here you press a button in the control cluster at the far left of the top plate to swap modes. If you’ve used high-end Nikons before this one, you’ll find the key controls pretty quickly – otherwise, it might take you a short while to learn the layout.

The D850 offers a clear, bright optical display (the largest yet on a Nikon DSLR, we’re told), while the GFX uses a highresolution clip-on electronic viewfinder – there’s even an optional tilting attachment. Some people prefer the clarity of an optical ’finder; others like the way an EVF can display the image the sensor will capture, complete with exposure, white balance and picture style adjustments. This is really a personal preference rather than one system being innately better than another.

On both cameras you can use the rear screen for composing images as well as the viewfinder. Both cameras use relatively slow contrast autofocus in this mode. Nikon does not have sensor-plane phase-detection AF technology, and the GFX’s sensor does not have the phasedetection AF capability of Fujifilm’s APS-C sensors.

It’s not a problem with relatively static subjects, however, and the advantage of Live View for the D850 is that you can

set the focus point across a much wider area than with viewfinder shooting. In Live View, you can also use the D850’s excellent silent mode, capturing fullresolution images at 6fps with absolutely no sound – very impressive.

Performance

For speed and responsiveness, the D850 wins hands down. The GFX’s combination of contrast autofocus and big lenses means that it can’t keep up with the Nikon for subject acquisition and tracking. But outside of sports and action photography, this is arguably less important, and you soon tune in to the GFX’s responses. It might not be the fastest focusing mirrorless camera on the market, but it’s perfectly usable,

and the expectations for a medium format camera will be different anyway.

If you need high resolution and the ability to capture fast-moving subjects, the D850 would seem to be the obvious choice, but if image quality is your sole concern, the GFX looks a very strong proposition – provided its image quality reflects the larger sensor size and cost compared with the Nikon.

And there are differences in the way these two cameras render images, which we explore in a lot more detail in our side-by-side image comparisons.

First, there’s very little to choose between these two cameras for exposure accuracy. Both delivered good, predictable results using their default multi-pattern metering systems, and we didn’t encounter problems with either camera. The auto white balance options gave quite different results, though. The GFX tends towards attractive, warmer tones in regular daylight, but shifted heavily towards magenta-red at dusk.

The results looked great, but they just weren’t realistic! The D850 tended towards duller, cooler tones in regular daylight, but stayed much more accurate in low and mixed lighting.

Outright resolution is a close call. After looking at lots of images side by side, we feel the GFX has an advantage for rendering ultra-fine textures and details. If you use a really good lens on the D850, though, it delivers resolution that’s practically as good as the GFX’s – you’d have to look hard to see the differences, and you’d have to be fairly fussy to consider them important.

There was little difference in dynamic range in our field tests. Surprisingly, perhaps, the D850 proved slightly better at holding on to bright highlights, but the GFX produced less shadow noise when bringing up darker areas in software.

For noise, though, the GFX is a pretty clear winner. The D850 has the higher ISO range, but the GFX produces less noise (and less obvious noise reduction in JPEGs) at higher settings.