Sony's 24.2-megapixel A6400 APS-C camera was a surprise, filling a gap between the A6300 and A6500 that didn't really need to be filled. Both in how it looks and the technology inside, it didn't seem like a great leap over the A6300. It also lacks important features (like in-body stabilization) found in the A6500. However, with 4K video, a pop-up screen, a microphone jack and reasonable $900 price tag, I thought it might make a great poor-man's vlogging camera.
- Excellent eye- and face-tracking autofocus
- Fast burst shooting speeds
- Improved programmable buttons
- Sharp video
- Bad rolling shutter
- No in-body stabilization
- Dated sensor
- No headphone port
Elsewhere, the A6400 packs a lot of incredible technology, especially in the area of autofocus, which makes it a significantly better camera than its predecessor. To find out how it stacks up against its close competitor, the Fujifilm XT-30, let's take a closer look.
Not many surprises here: The A6400 has a nigh-on identical body to 2016's A6300. The top, button layout, mount, battery and everything else is nearly the same as before. It has a magnesium body that's sealed against dust and moisture, as before, but Sony said it has been "mildly upgraded." The only difference I can see, however, is a slightly larger grip.
Gallery: Sony A6400 mirrorless camera | 23 Photos
Gallery: Sony A6400 mirrorless camera | 23 Photos
I've never been a fan of the button layout on Sony's A6xxx series. Rather than giving you lots of physical controls, you get just an (awkwardly positioned) adjustment dial on the top and a rear multi-function thumb wheel. Sony forces you to use the latter for many settings, like ISO and exposure compensation, which pulls your eye from the viewfinder. I much prefer what Fujifilm did with the XT-30, which also has a better-looking, more practical design than the A6400's square-black-box look.
Speaking of the viewfinder, the EVF is the same mediocre 2.36 million dot / 0.7x magnification OLED model as the one on other cameras in the family. Luckily, the rear display is a big upgrade compared to the A6400's predecessors. It's now touch-enabled, letting you tap-to-focus, track a subject and shoot. With no joystick, you can also use the screen to change the focus point with your eye to the EVF, much as you can with Canon's EOS R and other cameras. Unfortunately, you can't use the touchscreen to navigate the menus or quick settings.
The display's best trick, however, is that it now tilts down to 90 degrees and flips up and over 180-degrees. That lets you see yourself for selfies or vlogging, but there are some serious caveats that I'll detail shortly.
The A6400 has a microphone input but no headphone port. It also has micro HDMI and USB ports, but the latter is micro USB 2.0, not USB Type C, which is what Fujifilm's X-T30 has -- an unfortunate choice in 2019. On top of WiFi and Bluetooth, it packs NFC, to eliminate fiddling when you pair it with Android devices. There's just a single UHS-1 SD card slot, and it's powered by A6300's NP-FW50 battery, which yields 410 shots when using the touch display or 360 with the EVF. However, I found that the A6400 can take a lot more photos than that on a charge. It has a particularly long life when shooting video, too. Still, you'll need to carry a few extra batteries -- at least they're lightweight.
Sony's menu system generally gets a bad rap compared to Canon, Fujifilm and even Nikon, and it's well-deserved. It's frustrating to hunt through menu after illogically-organized menu to access key settings. Luckily, Sony has made the buttons much easier to customize, so my advice would be to set up the camera exactly how you want before shooting anything with it.
Lenses used to be a weak point for Sony, but that's no longer the case at all -- now, you can build a set of lenses that cover just about any shooting situation. The E-Mount system supports glass from both Sony's APS-C and full-frame FE mount lens lineup. It has become a very deep system, with around 18 Sony APS-C, 27 Sony FE and numerous third-party lenses from Zeiss, Sigma and others.
The A6400's body might be the same old, same old, but the electronics and software are new and very much improved. It has the same 24.2-megapixel CMOS sensor that we liked on the last model, but it now packs the latest Bionz X processor. That boosts the native ISO range to 100-32,000, expandable to 102,800, for one thing.
It also yields burst rates up to 11 fps with the mechanical shutter and 8 fps with the new, fully silent electronic shutter. What's more, you can fire off quite a few shots before the buffer fills: 99 for JPEGs and 46 for RAW files.
Shooting such bursts is pretty useless if the autofocus can't keep up, but that's where the A6400 really shines. The hybrid AF system has 425 contrast-detect and 425 phase-detect pixels that cover 84 percent of the imaging area. It makes better use of that tech than ever with new software borrowed from its quick-draw cousin, the full-frame A9.
Sony's real-time Eye AF and tracking features are powered by predictive and recognition AI. All you need to do is select your subject and it will lock on and hold it, and if it's a face, you'll get automatic face and eye detection. It'll keep tracking your subject, even when they look away, then lock on once they turn back. Sony said the AI system uses depth, pattern recognition and color to track subjects, all the way up to the maximum 11 fps shooting speed.
This feature is miles ahead of any other camera manufacturer's tracking/face/eye detection. I tested it with dogs, bikers and other subjects, and it helped me get the highest percentage of in-focus shots I've ever had at high burst rates, particularly with people. Obviously, it works best in good light, but I found it very effective even at ISOs as high as 12,800. That'll be particularly handy if you're trying to shoot sports in dim gymnasiums, for instance.
It's not perfect, of course. There are still moments when it loses track of subjects even though they're clearly in frame. Overall, though, Sony easily has the best AI eye- and face-tracking autofocus system on the market.
And it will only get better. Later this summer, Sony will release a firmware update that includes animal-eye tracking. Even if Sir Mewmew has particularly fluffy fur, the system will lock on its eyes to ensure the best shot. What's more, these features will be coming to Sony's A7 III, A7R III and A9 via future firmware updates. And it will benefit not just photographers but video shooters, too.
Now let's talk about my vlogging issues. It might be unfair to single out this feature on the A6400 because it does so many other things well, but Sony actually encouraged this idea by publishing not just one but two videos touting the feature.
The biggest problem is the lack of in-body stabilization. A lot of vlogging involves walking around while holding a camera, often while extending it by using a Gorilla Pod or monopod. To put it mildly, without stabilization, your viewers are going to get sick. The best you can do is get a stabilized lens zoom, but that's no match for an in-body system, and many of Sony's best primes aren't stabilized.
The A6400 and other Sony cameras suffer from pretty bad rolling shutter. When combined with that lack of stabilization and occasionally bumpy handheld video, it's a perfect storm of rubbery, wonky shots. I found that the A6400 has more jello than the Fujifilm X-T3 or Nikon Z6, both of which reportedly use Sony sensors, weirdly.
Another issue is the lack of a headphone port. Fujifilm showed that's possible on a budget camera like the X-T30 by letting you output audio over USB-C, so you can either use USB-C headphones or a simple dongle. It's a bad look for Sony that it can't do the same.
Vlogging is best done with an external microphone because camera mics tend to pick up a lot of ambient noise while yielding tinny, low-quality audio. However, if you install an external mic on the top hot-shoe, it blocks the screen, rendering the monitor useless. You can add a bracket to get it off to the side -- in fact, Sony conveniently sells a GP-VPT1 shooting grip for that very purpose -- but why not just have a screen that flips to the side like the GH5 or Canon's EOS R?
That said, the built-in microphone is actually good enough that many vloggers who don't need perfect quality could use it. I recorded much of this video with it and the quality is certainly acceptable, though clearly not as good as what I recorded with my Rode external mic.
And the autofocus system is just as good for video as it is for still photography -- all you need to do is touch your subject, and the system will track it. Much of the time, it's relatively automatic -- once selected, your subject will stay in focus, which is ideal for casual video shooters. While it's not quite perfect, this is the best AI face-tracking system on the market. The result? Better photos.
Since Sony kept the imaging sensor from the A6300 and A6500, you'd expect the images to look roughly the same. However, Sony does seem to have improved image processing a bit -- noise is better controlled at high ISO settings, for instance. JPEG photos look great right out of the camera, though noise reduction can be a bit strong -- I'd recommend the low noise-reduction setting to minimize that.
Gallery: Sony A6400 mirrorless camera sample images | 40 Photos
Gallery: Sony A6400 mirrorless camera sample images | 40 Photos
At the same time, Sony has gradually improved its color science, with images looking warmer and less green than before. The metering system does a good job with brightness and contrast, and clarity is excellent. All that said, however, the A6400's sensor is getting pretty old, and image processing can only take you so far. Meanwhile, Sony's main APS-C rival, Fujifilm, has updated its X-Trans sensors to newer, higher-resolution versions.
The same benefits and problems apply to video. As with the A6300 and A6500, the A6400 reads the entire sensor and downsamples it to produce 4K video. The result is excellent sharpness with minimal moire and aliasing.
The main problem arises when you start to move. With the same sensor as before, the A6400 is just as susceptible to bad rolling shutter as the A6300. That means you'll get a lot of skewing and rubbery-looking video if you do rapid pans. This problem is compounded by the lack of in-body stabilization. And, as with all its other mirrorless cameras, the A6400 can only record 8-bit, and not 10-bit video internally and externally. Once again, it falls short next to the Fujifilm X-T3 here.
The A6400 is not much of an upgrade over the A6300, other than the flip-up screen. It retains many of the pluses of its predecessor, like fast shooting speeds and 4K video, along with the disadvantages, including a lack of in-body stabilization and excessive rolling shutter.
However, the A6400 has more going for it than meets the eye. It has an all-new, incredibly advanced, face- and eye-autofocus tracking system superior to anything else on the market. Many users, especially amateurs, will get a far higher in-focus hit rate merely by selecting subjects and letting the camera do the work. This applies to both video and photos.
As for the vlogging aspect, the A6400 ends up being an okay mid-range option thanks to its decent built-in mic and pop-up screen. You need to understand its weaknesses, though. It lacks built-in stabilization and has a lot of rolling shutter, a combination that's especially brutal when you try to walk with or move the camera much.
The A6400 has stiffer competition than the A6300 did at launch. Most notably, Fujifilm's X-T30, which has a higher 26.1-megapixel resolution sensor and a lighter, classier body. It's not quite as fast as the A6400, but amazingly, can output 10-bit 4:2:2 external video, a feature lacking even in Sony's most costly full-frame mirrorless cameras. If you want to spend a bit less, the A6300 is available for $700, while the A6500 and its in-body stabilization costs about $200 more. Another option is Canon's $750 APS-C EOS M50, which shoots (cropped) 4K video and does have a display that flips to the side, letting you install an external mic.
The A6400 seems like a bit of a misfire. The autofocus system looks amazing, but Sony should have stuck it into an all-new, APS-C model, rather than a recycled A6300. Still, it's a great camera for shooters who want to maximize their usable, in-focus photos. Sony could (and needs to) do better, though, as Fujifilm and other rivals are catching up.