DxO One adds a new twist to the iPhone-connected camera

Sony invented the phone-connected-camera category with its QX series of lens cameras, but DxO is perfecting it. Unlike Sony's biggish and clunky Wi-Fi models, DxO's small, grip-size camera plugs into a Lightning connector, turning your

or into the display for DxO's 20-megapixel, 1-inch-sensor, f1.8 camera. And that's not its only trick.

This is probably the most elegant and functionally designed connected camera I've seen. While most of Sony's QX cameras are designed to appeal to more zoom-focused consumers, the DxO One is for advanced photographers who value photo quality more. It's got a fixed 32mm-equivalent focal-length lens which limits the audience for it. But then again, so does it the $600 price tag it will bear when it ships in September. In the UK it will cost £500 (VAT included), with delivery planned for Q4 2015; the company is still working on shipping in Australia "as soon as possible," but the price converts to about AU$775.

The DxO One is the company's first foray into consumer hardware; DxO routinely works with phone manufacturers on embedded imaging, but is more commonly known for its DxO OpticsPro raw-processing and DxO FilmPack effects software as well as its lens- and sensor-testing hardware and testing database.

Given DxO's background, it's not surprising that one of the most notable features is its SuperRaw format for low-light shooting. It works by combining four raw burst images into a single .DXO-format file. Unlike multishot HDR modes, which merge different exposures in order to render the broadest tonal range possible, DxO shoots multiple versions of the same exposure. It then compares them all -- in theory, the only pixels that should change between photos are noise (noise is random) -- and creates a noise-reduced version of the photos. This makes more sense to me than HDR for low light, because it should help preserve the night "look" and the contrast of the scene.

There are a couple of drawbacks: as with HDR it won't work very well if there's a lot of movement in the scene, and the processing of the DXO file has to be done on a computer with the bundled downloadable version of DxO OpticsPro 10.5 (an updated version of the software that will be available with the camera). For other formats it outputs Adobe DNG as well as JPEGs. It saves both to the microSD card and copies the JPEG to your Camera Roll; video records only to the card. When attached to the phone, you can stream video from the card as well as view the photos on it.

I'm impressed with how well-thought-out the design is. It's small: the dimensions are 2.7 x 1.9 x 1 in/67.3 x 48.3 x 25.4mm and it weighs 3.8 oz/108 g. The front has a cover that slides over the lens. When you slide it down, it turns the camera on; sliding down again pops the Lightning connector out of the side of the body. When connected to the phone, it acts as a grip, and has a real two-stage shutter button (for half-press prefocusing), though the camera uses an electronic shutter.

The connector mount can rotate 60 degrees forward and backward for up-high or waist-level shooting, or to help prop up the phone when it's sitting on a flat surface. If you connect the camera in the reverse orientation, it's ready for selfies.

Like the can-style cameras, you can use it detached from the device. However, since the One doesn't connect wirelessly, there's no viewfinder view and the photos don't transfer until you connect again.

A small touchscreen status LCD on the back switches between still and video modes with a swipe. Below the LCD sits a covered compartment with the microSD slot and USB connector, and there's a strap hook underneath that.

The camera has a six-blade aperture -- not round, but not bad -- and the optics consist of six aspherical lenses; most cameras have between one and three. (Normal lenses have simple concave or convex surfaces. Aspherical lenses have more complex, complementary curves to fit into a more compact space.)

For flash shots, it uses the

The accompanying app offers full manual controls, including the ability to stop down the aperture from f1.8 to f11, though you'll find usual full auto and program scene modes as well. The ISO sensitivity range runs from ISO 100 - ISO 12800, plus expanded modes up to ISO 51200, and you can set shutter speeds from 15 seconds to 1/8,000 sec. It can shoot 1080/30p or 720/120p video with slow motion playback, and though there's no image stabilization for stills, it does have electronic image stabilization for video.

My take

The big disappointments are the built-in battery's middling life of 150-180 shots and that it won't work with

phones. (It requires or later.) With its similar sensor, Sony's QX100 is its main competitor: for a slightly lower $500 (£380, AU$600) -- it looks like the QX100 is significantly cheaper than the One will be in the UK -- you get a 3.6x zoom lens, optical image stabilization and support, but the aperture for the f1.8-4.9 lens narrows very quickly, the device is bigger and the design and operation are clunky.

The Sony QX1 is just a mount with a bigger APS-C-size sensor designed to appeal to the same people as the One, but it gets pretty big equipped with a lens and suffers from the same clunky design.

As long as you don't crave a zoom lens and can stomach the price, it seems like the DxO One will be a great option for enthusiasts and pros. I'm seriously looking forward to giving the DxO One a shot.

Editors' note, June 18, 2015: I removed the specious discussion of dxomark scores. The company claims a maximum score of 85 on the standard sensor tests, which places it just above the Nikon D5500, not the mobile tests.