If you were hoping for the new Sony Xperia XZ2 models to feature a dual-camera setup, you were disappointed. Sony is by far the largest maker of image sensors but the Japanese manufacturer's own smartphone models still have to make do without the dual-cam technology that has almost become a standard on high-end devices.

That said, there is a good chance the wait for a Sony-branded dual-camera smartphone might be worth it. Sony executives told us the company was working on a dual-camera solution that would allow for low light shooting with ultra-high sensitivities - ISO 51200 in stills mode and ISO 12800 for video.

A test scene with extremely low illumination inside a black box is used to demonstrate the performance of the the dual-cam prototype (top) compared to a current model (bottom).

No further technical detail was provided at this point but given the camera module will be powered by a new "Fusion" Image Signal Processor, it's fair to assume the high sensitivities will be achieved by some kind of computational imaging process, merging image data captured simultaneously on the two sensors of the dual-camera.

This is not a totally new concept - for example Huawei is merging image data from an RGB and a monochrome sensor on some of its dual-camera models - but given Sony's bold high ISO claims there is a good chance its engineers have found another secret ingredient to boost performance to new levels.

Sony claims the new system is pushing smartphone low light performance into ILC territory.

A low-light demo setup behind the scenes at the Sony booth shows that the new system is capable of capturing good exposures in extremely dim lighting. Given Sony's typical announcement cycles, we'll probably have to wait around 6 months (i.e. until IFA in September) to see how the system performs in a production device but it's definitely something to look forward to.

The Fusion ISP is an essential component in Sony's upcoming low-light dual-camera setup.