Hands-on with the Sony a6400

Hands-on with the Sony a6400

The Sony a6400 is a refresh of the company's midrange APS-C mirrorless camera. Sony has taken the design of the a6300, retooled the LCD so it can now flip up 180° (for vlogging and selfies) and say it's made the body a bit more durable.

If that doesn't sound exciting, it's because we haven't told you about the a6400's most notable feature: its state-of-the-art autofocus system. But more on that - and a lot more - in the slides that follow.

But first, pricing. The a6400 will have an MSRP of $900/€1050 body only, $1000/€1150 with the 16-50mm F3.5-5.6 PZ lens and $1300/€1450 with an 18-135mm F3.5-5.6 lens.

Design

If you've used a Sony a6xxx series camera then you'll feel right at home with the a6400, since nearly everything is in the same place. While they have the same height and width, the a6400 is deeper than the a6300 due to the parts required to tilt the LCD all the way up. Something that serious vloggers may not like is that the LCD will be completely blocked by an external mic (or recorder). Even without those, the screen is slightly blocked by the top plate and EVF eye cup.

The a6400 has a magnesium alloy body and is sealed against dust and moisture. Sony says that the build has been 'upgraded,' but doesn't say exactly how.

LCD and EVF

Look familiar? The a6400 has the usual rear thumb wheel / directional controller, a few buttons, and a button whose function can toggle between AF/MF and AE-Lock at the flip of a lever. The camera has eight customizable buttons and dials and the 'My Menu' can store up to 30 of your favorite settings.

The 3", 921k-dot LCD on the camera still has a 16:9 aspect ratio, which is great for video, but results in black bars on either side of the image when shooting stills. Unlike the a63000, the screen is touch-enabled which allows you to tap-to-focus, shoot and track a subject. You can also use the screen as a touchpad to adjust the position of the focus point with your eye to the finder. The display can tilt down to nearly 90° and all the way up to 180°.

The a6400 uses the familiar 2.36M-dot / 0.7x magnification (equiv.) OLED EVF as the a6300 and a6500.

In-N-Out

There are a total of three I/O ports on the a6400: micro-HDMI, USB 2.0 and mic-in. There's also a 'Multi Interface Shoe', which is a hot shoe with electronic contacts for using an external mic, flash or XLR adapter. There's no way to connect headphones to monitor audio, though.

For those looking to transfer their photos onto a smartphone, you can use Sony's brand new 'Imaging Edge' app. The app, which replaces PlayMemories Mobile, offers a new UI, 4K video transfer and remote control. In theory it should support auto image transfer (at 2MP), but Sony currently lists the a9 as the only camera compatible with that feature.

In addition to Wi-Fi and Bluetooth, the a6400 also offers NFC, for quick pairing with compatible Android devices. Again, not much has changed over the a6300.

Memory card / Battery

In case you were wondering where Sony put the memory card slot, it's on the bottom, next to the battery (as usual). The a6400 supports SD cards (with UHS-I support) as well as yes-they-still-make-it Memory Stick Duo media.

We were a bit disappointed to see that the a6400 hasn't received a battery upgrade, instead relying on the old NP-FW50 for power. The official CIPA ratings for battery life are 410 shots with the LCD and 360 shots with the EVF, which are still respectable (you'll often get more than the rated number of shots). The battery can be charged over USB or with an external charger (not included).

Sensor

More than likely, the 24.2 effective Megapixel APS-C CMOS sensor on the a6400 is the same as the one in the a6300. And that's not a bad thing, as we found the image quality on that camera to be near the top of its class.

The a6400 incorporates the latest version of Sony's Bionz X processor, which allows for a wider ISO range. The native range is 100-32000, which can expand up to 102,800. Sony says that skin tones and 'plant colors' have been improved over previous models.

The a6400 has a fully electronic shutter option, allowing for silent shooting. The burst rate drops from 11 to 8 fps when using it, though that's still more than enough for most photography. Speaking of shutters, Sony rates the shutter life at 200,000 cycles: double that of the a6300.

Something that we really hoping for was sensor-shift image stabilization, like on Sony's a6500 and current full-frame models. Unfortunately, you won't find IBIS on the a6400, so you'll need to spend the additional money ($200 at the time of writing) if that feature is important to you.

Autofocus

We could write a thesis paper about the autofocus system on the a6400, but we'll keep it brief to preserve your sanity.

First, the basics: the a6400 has a hybrid AF system, combining 425 phase-detect points with a traditional 165-point contrast-detect system. Those phase-detect points cover 84% of the image area. So far, so familiar.

Now, the fun part. The a6400's AF system is based largely on the sports-oriented a9: at least after it receives a pair of firmware updates this Spring and Summer. Besides a speed boost compared to the a6300, the camera can take advantage of Sony's Real-time Eye AF and Real-time Tracking features.

Real-time Eye AF uses artificial intelligence that detects and processes eye data in real-time, allowing for fast recognition, speed and tracking. Users can specify the eye on which to focus or let the camera select the closest one. If you'd like, you can customize a button to quickly switch between eyes. After an update this summer, the a6400's Eye AF will be expanded to work for pets and wildlife.

Real-time Tracking uses all kinds of data - color, depth, pattern recognition - to recognize and track subjects at up to 11 fps, and we've been impressed by what we've seen of it so far. This video from Sony does a great job at demonstrating the two new real-time AF features.

Video

The video features, mostly shared with the a6300, are pretty good for a $900 camera. It captures oversampled 4K UHD footage (30, 25 or 24p) at bit rates of up to 100Mbps using the XAVC S codec. If it's slow motion video you're after, a 1080/120p option is available. As on existing models the 30p 4K capture is taken from a cropped region of the sensor.

One concern we have about video quality is with regards to rolling shutter. The a6300 had a lot of it, particularly at 24p and, since the a6400 appears to use the same sensor, we're not optimistic.

Video users do get many of the benefits of the new AF system though, with fast speeds, Touch Tracking and adjustable sensitivity, rather than the unreliable 'Lock-On AF' system in older models. Capture tools include focus peaking, zebra patterns, time code, clean HDMI output, proxy movie recording, and more. The a6400 is Sony's first APS-C camera to offer an 8-bit version of the HLG (Hybrid Log-Gamma) picture profile, which sits alongside S-Log2/3.

Finally, the a6400 has an interval shooting mode (about time) which can be edited into a time-lapse movie on the camera or via Sony's Imaging Edge desktop application.

Wrap-up

On the surface it might appear that not much has changed since the a6300, with the addition of a flip-up touchscreen and an HLG option for high dynamic range video not seeming to signal a major update. But then there's the stills and video autofocus.

To say that the autofocus system got an overhaul would be an understatement. We'll be spending plenty of time photographing bikes, running children and who knows what else in the next few days, but our early impressions of the Real-time Eye AF and Tracking features are extremely positive.