The iPhone quickly became my camera of choice as soon as I got an iPhone, and as its abilities have advanced, I've been happy with its performance. Of course it has limitations--low light photos are always difficult--but the tradeoffs have been worth it for the ability to take decent photos with a small, lightweight, connected device that I'm almost always carrying anyhow.
DxO wants to provide the best of both worlds: The convenience of shooting photos with your iPhone, with the image quality and RAW formats of a DSLR. The just-announced DxO One is a compact camera that attaches to your iPhone's (or iPad's) Lightning connector, so you've got an external lens, a real shutter button, and even space for a microSD card, but you compose shots and tweak settings on the iPhone's nice large screen.
The aluminum device is only 2.65 inches tall and weighs just 3.8 ounces, so you can easily drop it in a pocket when you're not using it. The lens is a f/1.8, 32mm equivalent aspherical lens with a variable 6-blade iris and a 1-inch, 20.2MP CMOS BSI sensor, which DxO says will help it capture great images even in low light. Once attached to your iPhone or iPad, the camera can still pivot up to 60 degrees up or down. And since the Lightning plug is reversable, you can also face the camera toward you for selfies.
An iOS app lets you control the camera's settings. You can adjust aperature from f/1.8 to f/11, shutter speed from 15s to 1/8000s, and ISO from 100 to 51200. Modes include Auto, Speed, Aperture Priority, full Manual, and several scene-specific options, and the camera interface adapts to each mode. Want to record video? No problem: Choose from 1080p at 30fps or 720p at 120fps.
The DxO One shoots in RAW format by default, producing DNG files you can use in Lightroom, Photos for OS X, and other editors. But this camera also sports DxO's brand-new SuperRAW format, producing propreitary DXO files currently supported by DXO Connect, DxO FilmPack, and DxO OpticsPro software for Mac and PC. (DxO Connect is included, and for a limited time the camera comes with licenses for DxO FilmPack and DxO OpticsPro as well.) DxO told me it was "engaging with Adobe, Apple, and Microsoft" to negotiate native support for the format.
SuperRAW sounds a little bit like HDR for RAW files: The camera captures four RAW images in quick succession, then combines them later in the DxO Connect app on your computer. The software uses spatial and temporal noise reduction, and the idea is to give you noise-free images even if you took them in very low light.
RAW images? High-def video? Are those file sizes pretty huge? DxO told me that the default RAW mode's DNG files are about 30MB--40MB, and the proprietary SuperRAW DXO files are between 120MB and 160MB. Those are a lot larger than the JPGs I shoot with my 8-megapixel iPhone 6 camera today: Big panoramas can inch above 12MB, but typical photos are 3MB or less. The good news is, you don't have to store the DxO One's images on your iPhone or iPad itself. You can opt to save to the device's Camera Roll, but to save internal storage, you could also choose to save to a microSD card you insert into the DxO One. Cards up to 128GB are supported, and a massive card like that can store more than 2600 full-resolution 20MP RAW images or more than 16 hours of 1080p video, according to DxO.
The DxO One ships in September for $599, and U.S. customers can preorder now. The biggest risk might be the Lightning connector: If Apple decides to change to USB-C in future iPhone and iPad models, you wouldn't be able to upgrade to the new version without making your expensive camera add-on obsolete. Apple typically announces new iPhones in September, the same month the DxO One is scheduled to ship, so if you're concerned about USB-C, you could wait and see. We'll have a full review once we can get a device to test.