Sony Alpha A6400 review

Meet Sony's all-new mid-range mirrorless camera

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Build and handling

  • Virtually identical design to Alpha A6300
  • Screen now rotates outwards 180 degrees
  • Features magnesium alloy body covers

Sony says the build quality of the Alpha A6400 has been upgraded over the A6300, although it's not clear exactly how or where. Either way, the Alpha A6400 features a magnesium alloy body which is sealed against dust and moisture. Sony's also bolstered the shutter, which has a lifespan of 200,000 cycles – double that of the A6300.

There's a pretty decent-sized handgrip, with the body of the A6400 following a virtually identical form factor to other A6000-series cameras. The A6400 also features an identical control layout to the A6300, with a good amount of well-marked controls at the rear, along with a free-moving control wheel that enables you to navigate menus and scrutinize images with ease.

However, as on all Sony's other cameras, touchscreen functionality is limited to tap focus, tap shutter and defining subjects for tracking; you're not able to navigate the A6400's comprehensive menu system, although this has been refreshed over the A6300's interface, with six color-coded sub-menus making it that little bit easier to navigate. 

A nice addition is the My Dial feature, which enables you to repurpose the Alpha A6400's main command dial and rear scroll when you press or hold a custom button. And this isn't limited to just one set of functions – you can configure up to three sets, assigning them to separate custom buttons or one that cycles between them. 

As we've touched on, the design does differ slightly from the A6300 thanks to the addition of a flip-out display that rotates outwards 180 degrees, which is more good news for those wanting to shoot selfies, and vloggers looking for a feature-packed 4K camera. One issue, however, is that if you're planning to use a dedicated external microphone and attach it to the camera's hotshoe, the display will be significantly obstructed. 


  • Focusing speed of just 0.02 sec
  • Advanced Real-time Tracking
  • Improved Real-time EyeAF

To say the autofocus system on the Sony Alpha A6400 is sophisticated is an understatement, and Sony's boast that the A6400 features the world's fastest autofocus at just 0.02 sec is just a small part of the story.

The new camera features a hybrid AF system, with 425 phase-detect points supplemented by 425 contrast-detect AF points (up from the Alpha A6300's 25 contrast-detect AF points), and delivers 84% coverage of the frame. 

This is the first Sony camera to come equipped with Sony's new Real-time Tracking and Real-time EyeAF technology (both features are coming to the Alpha A9 via a hefty firmware update in March, and to the Alpha A7R III and A7 III in April). 

Real-time Tracking uses Sony's latest predictive and recognition algorithms, including AI-based object recognition and color, subject distance (depth), pattern (brightness) and spatial information; that's not forgetting face and eye detection. 

EyeAF has been an impressive feature of many Sony cameras in the last couple of years, and the A6400's Real-time EyeAF looks to be the best implementation yet

This means photographers can specify a subject by selecting it with the AF initially, and the camera will then track it automatically round the frame. Rather cleverly, if the subject has a face, the A6400's AF will automatically use face and eye detection, but should the subject turn away the camera will revert to Real-time Tracking. 

EyeAF has been an impressive feature of many Sony cameras in the last couple of years, and the Alpha A6400's Real-time EyeAF looks to be the best implementation yet. Thanks to new AI algorithms, EyeAF delivers improved accuracy, speed and tracking performance, while the camera can now automatically track the preferred eye (left or right) of your subject. In the menu you can choose Auto / Right Eye / Left Eye depending on your preference, while there's the option to switch between left and right (assigned to a custom function).

During our time with the A6400 we've been nothing but impressed with its autofocus system. While it performs impressively when used simply for generic wide-area focusing in AF-S, it really comes into its own when you select continuous focusing and Real-time Tracking AF. Whether you're wanting to grab quick family snaps, or track and shoot fast-pace sports, the A6400's AF doesn't disappoint. Focusing is swift, and locks on to subjects with ease, while the fact that it will automatically detect faces and then eyes even more impressive. 

The A6400 did a good job of tracking this robin as it darted about in front of the camera. Sony Alpha A6400 with E 18-135mm f/3.5-5.6 OSS, 1/100 sec at f/5.6, ISO400
Phil Hall

Phil Hall is an experienced writer and editor having worked on some of the largest photography magazines in the UK, and now edit the photography channel of TechRadar, the UK's biggest tech website and one of the largest in the world. He has also worked on numerous commercial projects, including working with manufacturers like Nikon and Fujifilm on bespoke printed and online camera guides, as well as writing technique blogs and copy for the John Lewis Technology guide.