Testing: DxO One Compact Camera

By Norman Chan

A really interesting idea for a camera accessory that makes too many compromises to justify its achievements.

The camera on your iPhone or Android smartphone is pretty good. Good enough, and definitely convenient enough, to make most point-and-shoots obsolete. But those cameras will for the forseeable future be limited by their convenience--the need to fit the sensor and lens into a smartphone body (and god forbid, not bulge out from the back) constrains the type of camera hardware that can be used on a smartphone. That's why I think the smartphone is a great complement--not replacement--for a DSLR or large-sensor compact camera. You can buy lens attachments for a smartphone, but not swap out its sensor for a larger or more capable one. Yet.

The DxO One camera is a neat piece of technology that wants to give you the convenience of smartphone photography with the quality of a higher-end camera. It does this by cramming a big 1-inch type sensor and accompanying aspherical lens system into a really compact formfactor--something that weights just 108 grams and is about the size of a GoPro. And it can do that by not incorporating any sort of viewfinder or LCD display. That idea isn't new--Sony has its QX "lens-style" cameras that use a smartphone as the brains and viewfinder, but those cameras transmitted a video signal over Wi-Fi. The DxO One, which only works with iOS devices, sends its data back and forth over an Apple Lightning connection. Low latency, high bandwidth, resulting in a much more seamless and responsive camera experience.

I've been testing the DxO One for the past week, and brought it with me on a recent trip to Portland. We'll have a full in-depth video review soon, but here are my early thoughts on its strengths, weaknesses, and potential.

First off, the DxO One totally succeeds in terms of image quality, arguably the most important part of the camera. The sensor is actually sourced from Sony, and is the same 1-inch type sensor found in the awesome RX100 III (also my favorite compact camera). When compared to the camera on the iPhone 6, there's really no competition--the 20MP JPEGs that come out of the DxO One belong in the large-sensor class, not smartphone class.

That's also a testament to the f/1.8 lens that's packed into the DxO One's small formfactor. It's a six-element lens that doesn't pop out of the body, and has a six-blade aperture (more would be better). Plus, the DxO One can save RAW images locally to a microSD card for post-processing. The JPEGs that are stored in your iPhone or iPad's camera roll from the DxO One are really good--and more than suitable for sharing--but the RAW photos are just so much more versatile. DxO even has a "Super RAW" mode that snaps four RAW photos in succession (the faster the SD card the better) and lets you combine them with DxO's proprietary software to eliminate motion and get effectively more stops of light.

iPhone 6 on left, DxO One on right

In my testing, the places where the DxO One stood out were portraits and low-light photos. The iPhone's fixed 28mm lens has to strike a balance for all the types of photos that people use it for--from landscapes to macro shots. It's not really idea for single-subject portraits from a close distance. The DxO One's 32mm equivalent lens is tighter, and resulting portraits look much more flattering. Since it's a fixed lens as well, I would actually have preferred 35mm, if it was possible.

Another area where the DxO One succeeds is its robustness as a mobile camera. With the iOS app (which automatically launches when you plug the camera in), you have full PASM controls, metering and white balance adjustments, and even a manual focus slider. The interface is simple to use and looks great on both iPhone and iPad. Photos automatically get saved to the camera roll, so you can throw them up on Facebook or Twitter without tethering later. The app-based nature of the camera also means that DxO can improve the experience with updates as more features are developed. Compared to the RX100, the DxO One app is missing some key photography features like ISO bracketing, shutter minimum, photo ratings, and burst modes. Updates are supposed to come every two months, so I'm hopeful for what this camera looks like in a year.

iPhone 6 on left, DxO One on right

For taking photos, there's actually a physical two-stage shutter on the device in addition to the app button. That means you can take photos without any iOS device connected (as you could with a GoPro). I actually really liked walking around Portland with the DxO in my pocket, taking it out from time to time to snap photos without even having to take the phone out. A little more inconspicuous, and and a little more spontaneous, which was fun! There are definitely novel benefits to having a good camera of this size.

But after a few days of shooting, I ran into the limitations of that design. First of all, autofocus ended up disappointing me. The Sony RX100 sensor actually doesn't have any phase-detect points, so the DxO One has to rely on contrast detect and facial recognition for its autofocus. This is slower than I would like, and was occasionally inaccurate. Slow autofocus means this camera is best for still subjects and not motion. DxO says that this is a camera that should complement your phone, so you'd ideally use it when you have time to plan out a scene and take a more measured shot.

That rationale is also to mask the fact that the battery life on this camera is mediocre at best. DxO claims that you can take 100-150 RAW photos in succession, but in real-world use, I was never able to take more than 75 photos in one charge, using it throughout the day. The small battery capacity was a necessary design decision for the camera's small size, and it would be reasonable if you could also charge the device from the lightning connector, like in Apple's upcoming Pencil accessory. Instead, you can only charge it over a microUSB connection. It also got pretty hot after continuous use of about 15 minutes. Again, fueling the "use as a complementary camera" suggestion.

iPhone 6 on left, DxO One on right

Third, I really wish that the camera was more functional when used as a standalone device. For $600, I want to be able to use it to replace the RX100 or similarly classed compact camera. And while there is the dedicated shutter button, there's no way to load shooting presets onto the camera for snapping shots freehand. The camera actually has a small monochrome touchscreen OLED display on its back, which you can use to swipe between photo and video modes. This would've been a perfect way to tap to load presets or make small adjustments. Currently, the DxO One defaults to an Auto photo mode when not plugged in to a smartphone.

Another nitpick: the lens has a pretty long 20cm minimum focus distance, which prevents you from taking any macro photos.

At $600, the DxO One is very much a boutique device for a niche market. The RX100 III costs $800, and I understand that large camera sensors are expensive, but the advantages of size and portability don't outweigh the limitations of short battery life and fixed lens. I'll be very interested to see how the app and camera firmware improves over the coming months. There's a lot of potential for cool features to be incorporated, especially when the camera can tap into data from the iPhone, like IMU tracking for video stabilization. But as we always say, don't buy a product for what it promises--buy it for what it is today. You can check out my test shots in this Imgur gallery.