Our latest test scene simulates both daylight and low-light shooting. Pressing the 'lighting' buttons at the top of the widget switches between the two. The daylight scene is manually white balanced to give neutral grays, but the camera is left in its Auto setting for the low-light tests. Raw files are manually corrected. We offer three different viewing sizes: 'Full', 'Print', and 'Comp', with the latter two offering 'normalized' comparisons by using matched viewing sizes. The 'Comp' option chooses the largest-available resolution common to the cameras being compared.

The GFX 50S's resolution capture is, as you might expect, impressive. That said, the Canon EOS 5D SR, shot with the relatively lowly 85mm F1.8 lens is able to do a similar job. All four cameras, with good prime lenses on are exhibiting moiré in the finest detail in the scene.

In terms of high ISO noise, the GFX 50S performs fairly similarly to the Pentax 645Z and, as sensor size alone would lead you to expect: better than the Canon EOS 5DS R. However, because Sony's a7R II sensor uses a more modern BSI design, it's able to be more efficient, which means it's able to close the gap to the bigger sensor cameras. 

The GFX 50S's JPEGs are every bit as pleasant as they are in the company's smaller cameras. Color response is bright and punchy, with both skies and skintones well represented. And, of course, the Film Simulation modes mean there are a selection of good-looking options available. Default sharpening is quite strong but is effective at emphasizing fine detail in the scene: taking the level of apparent detail ahead of its rivals, without adding too much in the way of haloing at high contrast edges.

Similarly, noise reduction does a good job of balancing the retention of detail with the suppression of noise. We're not sure many people are looking to buy a medium format camera to shoot JPEG but they're very usable even at the camera's highest setting. Which just makes it seem more peculiar that Fujifilm limits the camera to a relatively modest ISO 12,800.

Dynamic Range

Looking at our ISO Invariance tests, we can see that an image shot at ISO 100 and pushed six stops looks noisier than one with the same exposure, shot at ISO 6400. This shows that the sensor is still contributing a little noise to its images (enough that you'll see it, if you multiply it 64 times!). However, the 5EV push of an ISO 200 shot looks a lot like the ISO 6400 image, which suggests it's a very good sensor.

However, the exposure latitude test, where we lift the shadows in images shot at progressively lower exposures shows that its performance is only slightly better than that of the D810, despite receiving more total light (double the exposure time and half the light per square cm, captured on a sensor with more square cm of area). Now consider the fact that the D810 has an ISO 64 mode, which would allow you to use a 2/3EV brighter exposure before the sensor clips. We expect this will give a real-world result similar to when we pitted the Pentax 645Z against the Nikon.

However, Fujifilm does claim to have increased the 'Photic Saturation Point' (by which we assume they mean 'full well capacity'), by 1/3EV so we'll need to conduct a full expose-to-the-right side-by-side test to be sure.