If you didn't know anything about Sony's Cyber-shot QX100 and QX10 cameras, you'd probably think they were just lenses and not full cameras. Basically, Sony fit entire cameras into relatively small cylindrical bodies.
The cameras directly connect via Wi-Fi to iOS and Android devices (there are no plans for Windows Phone support), which gives you a screen for framing your shots and controlling the camera. However, if you just want to take a quick photo, you can shoot blindly using the camera's basic built-in controls.
The QX100 has the key ingredients of the $750 Sony Cyber-shot DSC-RX100 II. Targeted at enthusiasts, the QX100 features a large-ish 1-inch-type 20.2MP Exmor R CMOS sensor paired with a Bionz image processor. A Carl Zeiss-branded 3.6x f1.8-4.9 28-100mm zoom lens is out in front.
There is no physical connection between the camera and your smartphone. The camera "attaches" to your device with a tension clip on the back of the camera. The fit is reasonably tight, but probably not secure enough to only hold your smartphone when it's clipped on.
It doesn't need to be clipped onto a device at all, though, so you can hold the camera in one hand (or mount it on a tripod) and shoot wirelessly.
Though you won't be able to see what you're shooting without a smart device, you can still take pictures and use the zoom lens with the camera's built-in controls.
Most of the time, you'll be using a smartphone to control the camera, though. Shooting modes include Sony's Intelligent Auto, Superior Auto (that's Intelligent Auto plus some multishot options for low-light and backlit shooting), Program Auto, Aperture Priority, and Movie. You can adjust white balance, exposure compensation, and ISO. Autofocus is multipoint and light metering is multipattern. There is manual focus, though.
The QX100 captures JPEG stills only (no raw) and record movies at 1,440x1,080-pixel resolution at 30fps in MP4 format.
If you have an NFC-enabled device, you simply bump your device against the little NFC logo on the camera and it will automatically launch the Sony PlayMemories Mobile app and establish the Wi-Fi connection between the camera and device.
The QX100 weighs 6.3 ounces and measures 2.5 inches wide by 2.5 inches high by 2.3 inches deep when closed. By comparison, the RX100 II is a little more than 3 ounces heavier and measures 4 inches wide by 2.3 inches high by 1.5 inches deep. Worth noting, too, is that by shedding the traditional camera body, there's no flash built into the QX100.
It uses a Sony lithium ion rechargeable battery that's pretty easy to come by. Sony claims a battery life of up to 220 shots and a movie recording time of 25 minutes.
Shooting performance sounds pretty good once it's up and running. Startup takes 6.9 seconds with a shot lag of 0.21 second and a shot-to-shot time of 1 second. This is under ideal conditions, though, so shooting in low light or wireless interference will likely slow it down.
There is a microSD card slot that can be used with cards up to 64GB. The slot will also take Memory Stick Micro cards up to 16GB. When connected to a smartphone, the camera will store full-resolution photos to the card and 5-megapixel shots to your device for easier editing and sharing.
There is also a Micro-USB port for charging the battery as well as transferring photos and movies.
The QX10 is for those who love their smartphone's camera, but miss the zoom lens. It features the 10x, f3.3-5.9, 25-250mm lens and 18-megapixel, 1/2.3-inch backside-illuminated CMOS sensor of Sony's ultracompact WX150 from last year.
The use of a smaller sensor allows you to use a smaller lens. Despite the QX10's 10x zoom, the whole unit weighs only 3.7 ounces and measures 2.5 inches wide by 2.5 inches high by 1.3 inches deep. Not as easy to pocket as the camera it's based on, but not as bulky as the QX100.