Do you remember when cellphones did not have a camera in them and some manufacturers, like Nokia, would actually sell an external digital camera for smartphones?
They would also sell external cameras for simpler phones so that you could shoot 0.3 MP images and then upload them to the phone.
Well, smart phones have come a long way since then: from absent to nominally present, from nominally present to mediocre, from mediocre to pretty good, the cameras on your cell phone have evolved.
Today, the camera that your cell phone is equipped with is of good quality. At ideal daylight conditions they are now able to get visually indistinguishable pictures from mid-range cameras on a Full HD screen or in print 10x15 cm (4x6"), but is the good performance in ideal conditions good enough? Aparrently not. At least that's what the guys from the DxO company thought.
So, since they had a lot of experience with camera testing they decided to come up with their own hardware product. But instead of trying to compete in the inundated market of pocketable digital cameras, they came up with something new. Their camera – DxO One – is not a camera strictly speaking. Instead it is an attachment for the iPhone which connects to it via the lightening port. The logic being that you already have a very powerful processor and great quality display in your smartphone, so why double their functionality? Instead let's make use of what you already have in your pocket (big gorgeous display and super-fast processor) and add what you don't have (a relatively large, amazing sensor paired with quality optics). Also, let's make full use of all that computing power (btw, iPhone 6S has more of it than 13" MacBook Pro released in 2010) and our experience with software for one of a kind processing resulting in what is called "SuperRaw". Plus, let's add a memory card slot in order to avoid stuffing up the iPhone's memory. Do as described above and you get this:
Well, it's definitely smaller and lighter than a point-and-shoot would be, but how good is it actually? The answer is pretty damn good (according to specs). This camera features the same 1" 20 MP sensor found in our top pick for pocketable camera – Sony RX100 III – and fast F1.8-F11.0 32 mm (equivalent) lens. That's not too bad at all; but we all should know by now that specs are not all you need to take great photos or be able to sell them on microstocks, so without farther delay let's compare shots with the above-mentioned RX100 III:
As you can see the DxO One is not quite there, despite having the same sensor. This is, of course, due to the optics that were packed into such a small body and so close to the sensor. Of course this was tough competition for DxO One as we compared it to the best compact out there. But since the cameras cost the same the fact remains: DxO One won't give you the best quality for you money, neither will it be the silver medal winner. Bronze? Perhaps. As for compactness, yes, for this size and weight, image quality definitely doesn't get better then this.
Unfortunately, you will compromise not only image quality but also ergonomics, as shooting with a smartphone attached will never be as convenient as with a dedicated camera. Of course, you can also shoot without the smartphone in the "general direction of the subject" as the camera's manual reads, but that's also a huge compromise. Something like this is OK to do with a GoPro but not with a device you bought specifically to get better pictures than with your smartphone.
So, should you buy it? If it were $300 – this would be no-brainer. But for $600? I'd say it's not worth it, unless you're into unusual stuff for the sake of it. But as always – the decision is up to you.