Image Quality

Our test scene is designed to simulate a variety of textures, colors and detail types you'll encounter in the real world. It also has two illumination modes to see the effect of different lighting conditions.

The RX10 IV uses Sony's latest 20MP 1-inch type sensor. It brings on-sensor phase detection but offers no significant image quality advancements, in terms of Raw captured, when compared to its predecessor. Raw performance is nearly identical to that of the RX10 III, which is to say excellent.

There are some changes in JPEG performance though: they appear a tad sharper which means better retention of small details compared to its predecessor. At high ISO's, there is a tendency to smear color detail due to aggressive noise reduction. However the improved sharpening does mean slightly better detail retention at ISO 12,800, even in very low light. Simply put, the RX10 IV has some of the smartest JPEG sharpening in its class. And if you turn down the default noise reduction in camera, smeared color at high ISO is less of an issue.

Dynamic Range

In terms of dynamic range, there's only a small difference between shooting at ISO 1600 and shooting at ISO 100 and brightening later. This suggests the camera is adding very little electronic noise to its images. It also means you're often better off using a low ISO and brightening rather than using a higher ISO, since this way of working will retain more highlight information.

That said, although the performance of the RX10 IV is essentially a match for that of the RX100 IV, the small sensor means that any reduction in exposure quickly adds to the noise level, so it's important to give the camera as much light (by opening the aperture or lengthening the exposure time) as the camera will tolerate.

Video Quality

The RX10 IV's closest video competitor is the Panasonic FZ2500 - both are capable of good 4K video quality, but ultimately use different methods to capture it. The Sony over-samples an area of the sensor and then downsampling the image to 4K in-camera - the Panasonic uses a native 4K crop of the sensor. The result is Sony has better detail capture, where the Panasonic shows aliasing (see above). The RX10 IV also has a better quality lens, which further contributes to its superior 4K video detail retention compared to the Panasonic. This is evident throughout the test scene.

4K video looks fairly similar to that of its predecessor the RX10 III, which we expected. The same goes for 1080/24p, it also looks similar.

It's worth noting that there is a slight crop factor of 1.09x when using the RX10 IV to shoot 4K. And when employing the camera's various digital stabilization options in Full HD, you will also experience some cropping (and resolution cost). See below:

100% crop from mode selected below.

As you can see, using the camera's digital stabilization has a resolution cost.
IS Off / Standard (Optical) IS Active IS iActive