Build quality and handling

  • Sturdy design
  • Standard tripod thread
  • Easy to switch on and off by accident

Smooth, solid and well constructed, the YI 4K starts up inside a second; there's another delay of about two seconds before it’s truly ready to go, but that's still impressive, and very useful on an action cam.

The one-press shutter makes the YI 4K easy to operate – in fact it's arguably too easy, as the button is exactly on the spot where you'd naturally pinch the camera to pick it up, making it almost inevitable that you'll depress the on/off button by accident. So at some point you'll probably create a five-minute 4K video of the inside of your pocket, as we did, which could potentially leave the battery drained. 

Unlike the GoPro Hero5, the YI 4K Action Camera is not waterproof, and there's no waterproof case included – that accessory will cost you $39.99/£30.99, and it's good to a depth of 132ft/40m, although it effectively renders the touchscreen useless. 

The standard tripod thread on the camera's underside is a nice inclusion, although once it's mounted the fixed 155-degree field of view does feel slightly restrictive.

There are enough creative modes to keep most filmmakers happy – loops, timelapses, slow motion (1/8, 1/4 and 1/2-speed), a countdown timer, and a 30 fps burst mode are all here. 

Performance

  • 16 resolution and frame rate combinations
  • Simple on-screen menus and phone app
  • 155° wide-angle lens can create distortion

We tested the YI 4K Action Camera in a variety of situations, from indoors to around Westminster Palace in London, and while hiking among the mountain-top telescopes of La Palma in the Canary Islands. 

The YI 4K creates its own Wi-Fi Direct network, so you just need to find it on a phone before launching the excellent YI Action app. Although the app streams a live view from the camera to the phone, that's largely not necessary given the YI 4K's touchscreen, which can also be used to make adjustments to all the core settings. 

A settings dial gives you access to on-screen menus for the camera or video functionality, depending on what's currently activated. There's a mess of resolutions and qualities to play with, perhaps too many; the very highest resolution video is 4K at 30fps, with video quality set to high, while you can go right down to 480p, though that does come with the advantage of a whopping 240fps. For photography, 12 megapixels is the top choice, though sadly there's no raw format option. 

For stills photography, JPEGs need a boost of levels, and there's no raw support

The likes of white balance, ISO, exposure compensation and metering modes can also be tweaked for both video and photos, and the on-screen menus are bright, easy to understand and work very quickly. However, there's no voice control on offer, unlike on the GoPro Hero5.