Sony's recent financial statement saw the point-and-shoot business in decline, while high-end cameras were on the rise. People passionate about photography are going for the high-end cameras that are getting more accessible and more capable, while everyone else just uses their smartphone.
Sony is jumping ahead of the curve by introducing a brand new type of device - the Cyber-shot QX line of lens-style cameras. They consist of a lens, image sensor, image processor, battery and wireless connectivity unit and rely on a smartphone to act as primary controls, viewfinder and advanced features.
By removing components Sony will be able to offer the key elements of a camera (lens and sensor) cheaper than if the company had to build an entire camera around them. This way you don't have to buy a new smartphone or even pay the full price of a camera but you can still get a good sensor and 10x optical zoom with QX10 or grab the acclaimed Sony RX100M II at a sizeable discount.
Each camera has a clamp that allows it to attach to a smartphone though that's not strictly necessary, the communication is done wirelessly. The clamp can hold the Xperia Z1, which is fairly wide and we don't think most smartphones will be a problem for it.
Sony is offering another way to attach the QX cameras, this one aimed specifically at the Xperia Z and Xperia Z1. It's a back cover with a circular hole in it where the camera goes. It's a cleaner solution that using the clamp and it offers some extra protection for your phone when the camera is removed (because if it's still attached, you'll want to be careful with it as such optics are not very resilient).
NFC is used to pair the camera and the phone quickly, then Wi-Fi takes over and streams a live feed from the camera to the smartphone. The cameras have hardware On/Off buttons on them along with the basic controls - a zoom lever and a shutter key - though you can control those features via the phone's interface (and most of Sony's phones have a dedicated shutter key). There's also a standard tripod mount at the bottom.
The Sony Cyber-shot QX100 lens-style camera consists of ZEISS Vario-Sonar T* lens with a fast F/1.8 aperture, optical image stabilization and 3.6x zoom, 1" 20.2MP Exmor R sensor and a BIONZ image processor.
The Cyber-shot QX100 is the bigger of the two devices and if you didn't know better, you'll mistake it for a DSLR lens. It's cylindrical in shape and while it's in no way pocketable, it's still smaller than the Sony RX100M II. It's lighter too, so your phone with the QX100 on is easier to carry than a phone and a RX100M II camera.
The QX10 is based on the Sony WX150 - Sony G Lens with F/2.0 aperture, optical image stabilization and 10x zoom, 1/2.3" 18.2MP Exmor R sensor and BIONZ image processor. It's similar to the Sony Xperia Z1's camera in terms of specs (aside from the optical zoom and OIS, of course).
The QX10 is actually compact, despite having a longer zoom. It looks like a pancake lens and while it's probably still a bit too big to pop into your pocket, it's easy to carry around.
This is another problem that Sony is solving with the Cyber-shot QX line - something like the Samsung Galaxy S4 zoom has a 1/2.3" sensor and 10x zoom too, but it's too bulky for an everyday phone and most people won't buy a "vacation phone", but with a QX detachable camera, you can easily switch between portability and high-end imaging.
Both cameras can record 1440 x 1080p video at 30 frames per second (that's 1080p video cropped to 4:3 aspect ratio). We have to say that's disappointing as even mid-range phones can shoot 1080p video and 4:3 video is not all that useful.
One potentially big issue with getting a QX camera instead of a traditional camera is that the lens-style cameras lack their own flash and rely on the phone for that. And Sony doesn't have a xenon flash on any of its phones and single-LED just won't cut it in some situations even with a large 1" sensor and optical image stabilization.
Another potential issue is that you have two separate batteries and both of them are feeding a wireless connection. That's an extra power draw and if one of the batteries runs out, the setup no longer works. That also means there are two batteries to charge (though that's true about having a separate camera as well).