Sony a6400 Review (2024)

The Sony a6400 ($899.99, body only) isn't the sexiest, flashiest camera to come from the brand in recent years—most of the buzz comes from the company's full-frame line. But not everyone wants or needs a big sensor. The APS-C format delivers a solid balance of size, image quality, and depth of field control, and is still what you find in most consumer cameras. Sony's latest entry in its APS-C mirrorless line inherits some features from its pricier siblings. It's a fine successor to the a6300, and earns our Editors' Choice award.

EVF and a Selfie Screen

The a6400 ($898.00 at Amazon) looks a lot like the a6300 ($944.95 at Amazon) . Sony hasn't made a major design overhaul to this style of camera in years, although there have certainly been incremental changes from model to model. The camera is available only in basic black—silver editions of others in the series have come to market in the past, but typically well after the initial announcement. It's compact, measuring 2.8 by 4.8 by 2.0 inches (HWD) and tipping the scales at 14.3 ounces (both figures without a lens).

The a6400 is sold as a body only for photographers who already have an investment in compatible lenses. Sony also bundles it with the compact 16-50mm f/3.5-5.6 zoom for $999.99, or with the longer 18-135mm f/3.5-5.6 for $1,299.99. Both kit lenses include optical stabilization, a plus since the a6400 doesn't.

Sony wants you to move up to the a6500 ($1,298.00 at Amazon) to get an APS-C camera with in-body image stabilization (IBIS). The a6500 is a couple of years old now, and doesn't quite match the a6400's advanced autofocus system in performance, but it remains a solid, if not class-leading, performer.

The camera does include an in-body pop-up flash, an EVF, and a hot shoe. You don't always get all three in a mirrorless camera. Pros may scoff at the small pop-up strobe, but it's definitely a step up from the flashes you'll find in consumer SLRs for a simple reason—it's mounted on a hinge. This means you can pull it back with your finger and bounce light off the ceiling to get softer, more even illumination.

Take a look at the side-by-side comparison above—the shot on the left was captured with the flash pointed forward, and the one on the right was shot with it pointed to the ceiling. It's a bit of a hack—there's no way to lock the flash in position to bounce—but if you find yourself using the feature frequently, some gaffer tape can keep it pointed up.

There is a modicum of weather protection. Sony states the a6400 is only protected from the elements, with the caveat that it is "not guaranteed to be 100 percent dust and moisture proof." In layman's terms, don't take the a6400 out in a monsoon or blizzard, but you can feel comfortable shooting in less intense precipitation. It will also help if you use a full-frame (FE) lens, as they offer weather sealing that standard APS-C (E) lenses do not.

If you're mulling an upgrade from an a6300, be happy to know that the physical controls haven't changed one iota. The camera eschews front buttons, aside from the one used to unlock and unmount the lens. The top controls are all at the right side. The On/Off switch surrounds the shutter release, and is atop the handgrip, at a slight angle. Next to it is the programmable C1 button.

Two dials are located behind them. The Mode dial changes between automatic, manual, and other standard shooting modes. There are some changes here versus the a6300. The a6400 offers access to MR, which lets you recall one of three saved banks of settings, and it replaces two separate dial positions for the a6300's two available custom profiles. A new S&Q mode is Sony speak for Slow and Quick Motion, which is slow-motion video, at up to 120fps at 1080p quality.

On the rear you find the mechanical flash release just behind the flash itself, toward the top of the body. It's joined by the Menu button just to its right, and the AF/MF and AEL control, which is a two-function button with operation changed by a toggle switch that surrounds it.

All the way right, practically on the side of the camera, is the Record button for video. It's awkward to reach, and recessed so you don't trigger it accidentally. I think its position makes sense if you're primarily a photographer who occasionally dabbles in video. If you plan on using it frequently, it's in an incovenient spot. Thankfully you can reprogram other buttons to start video—I found the C1 button to be just about perfect. Unfortunately there's no way to remap the Record button's function.

The other rear controls run down the right side, in between the LCD and the body's edge. You get Fn, which brings up a customizable on-screen menu that provides access to up to a dozen additional functions.

The rear command dial is flat, but turns comfortably. It's another control you can remap, but typically you'll use it to adjust the f-stop, shutter speed, or EV compensation, depending on which mode you're in. It has the OK/Enter button at its center, and directional presses adjust ISO, EV, Drive, and the information overlay display. Any of these four directional press functions can be remapped.

Finally you get the Play and Delete/C2 buttons, nestled in between the bottom edge of the wheel and the bottom of the camera itself. As you'd expect, the Delete/C2 button's function is customizable during image capture.

The 3-inch LCD is a touch screen, an upgrade from the a6300. It offers the same 921k-dot resolution, but the hinge has been redesigned. The screen doesn't just tilt up or down, as with other models in the a6000 family, but also flips forward for selfies and vlogging. The screen is sharp, and wide with a 16:9 aspect ratio. When taking selfies, a three-second countdown timer automatically engages, so you can make sure you're ready for the shot.

Touch input isn't available everywhere. Primarily you'll use it to set an autofocus point—it's especially handy for overriding automatic focus point selection when needed—and you can double tap the screen to punch in and check focus on an image in playback mode. But you can't use it to navigate Sony's menu system, which is better than it used to be, but still pretty dense.

There are some menu improvements with this model. On-screen help is available to tell you what a function does, and you also get a customizable My Menu page and there are illustrations to make it easier to change the function of the programmable buttons. Enthusiasts should set up My Menu—it'll save you time in the long run—and most casual family snapshooters can get pretty good results without fiddling with settings.

The EVF is similar to the one found in the a6300. It's an OLED panel with 0.7x magnification and 2,365k dots squeezed into its small frame. The finder isn't the largest you'll see in a mirrorless camera, but it's very competitive with others in this price range in size and resolution. I've got very little bad to say about the EVF—I don't think you'll be disappointed in it, even if you're looking at the a6400 as a secondary camera to supplement your full-frame Sony mirrorless body.

One more feature of note, mainly because it's new to the a6000 family, is a built-in intervalometer. It allows you to capture photos at set intervals, with the intention of combining them into a time-lapse video. The a6400 doesn't make the movies in-camera—you'll need to use the software Sony provides or your favorite video editing program to make the finished video. Software as basic as iMovie and as advanced as Adobe Premiere Pro will let you do it, and the a6400's 24MP sensor provides enough resolution to deliver time lapses at 6K resolution.

Connectivity and Power

As you'd expect, the a6400 includes wireless connectivity. It supports Bluetooth, NFC, and Wi-Fi. Thanks to a recent update to iOS, Apple users can now pair the camera with the Sony PlayMemories Mobile app with a tap, just as Android owners have been able to do for ages.

It's easy enough to transfer images and video to your phone—once you've got the two devices connected you can tag and send photos from the camera, or browse memory card contents using your smartphone. Remote control is also available, complete with a live video feed to your phone's screen.

The a6400 has a 3.5mm microphone input along with micro HDMI and micro USB 2.0 ports on its left side. The battery—the W style Sony has used in the a6000 series and other models for years—is the power source here, although you can run the a6400 from a USB power bank or AC adapter. It's rated by CIPA for 360 shots using the EVF or 410 using the rear LCD.

Those seem like good estimates after two full days of using the camera in the field—I managed around 450 shots using about two-thirds of a charge, but the figure benefits from a liberal use of burst shooting. I did mix in some video capture; CIPA rates the a6400 for about two hours of continuous recording time. Sony doesn't include an external wall charger to replenish the battery outside the camera, but does bundle an AC adapter and micro USB cable for in-camera charging. I love the convenience of charging via a USB battery or from my laptop, but I think a charger should be included too. This is a camera where a spare battery is something you'll want to buy, especially when you're on a vacation or the like.

Videographers discovered that the a6300 had a tendency to overheat when recording long video clips. I tried to get the a6400 to overheat when recording video at 4K quality, but to no avail. There is no 29-minute recording limit, so you'll be able to record footage until your memory card fills up or the battery empties.

The SD card loads in the bottom, in the same compartment as the battery. The slot also supports Memory Stick, but no one uses Memory Stick. You'll want to get an SDXC in order to take advantage of all of the a6400's video features, but bear in mind the camera only supports UHS-I speeds. Even if you buy a fancy 300MBps UHS-II memory card, the a6400 is only going to push files to the card at about a third of that rate.

Fancy New Autofocus

The a6300 is no slouch when it comes to capturing fast action, but it's also not the best out there—perfectly understandable given its price and position in the market. Sony claims the a6400 has the world's fastest focus acquisition, and our tests show that it can lock on to a subject in less than 0.05-second, which scans with Sony's 0.02-second claim. We're currently using an analog-style timer to check focus speed, and it doesn't deliver the precision required to measure durations as short as 0.02-second.

See How We Test Digital Cameras

Focus acquisition isn't all that goes into autofocus. The a6400 includes many of the same focus functions as the a6300, but drops Sony's older Lock-On AF subject tracking for a new system, which is identified more simply as Tracking in the camera menus. It's only available in AF-C, so if you leave the camera set to the default AF-A mode you'll be limited to using the older focus modes. That's not a bad thing for casual users, as they work pretty well. But if you're photographing subjects moving through the frame and want to track one in particular—say your child at a sporting event—it's useful.

The Tracking mode uses some machine learning features to better identify and track subjects. It takes the same data as the standard focus mode—color, distance, and face detection—and adds real-time eye detection and pattern recognition to better identify and track subjects. In my testing I found that it works very well. The camera can still miss focus on occasion, but for the most part does a very good job keeping your subject in focus. At press time the Eye Detection feature works with humans only, but a firmware update (slated for release this summer), will add support for animals as well.

It's not uncannily good, which is where I'd place a camera like Sony's top-end a9 (which is getting the new Tracking focus mode via a firmware update in the spring). I found that foreground subjects could throw the autofocus system off a bit. Not so much with the tracking but with initial acquisition. The camera was quick to focus on a volleyball net rather than the player on the other side of it, and was also prone to lock onto artificial snow, which was an aspect of one portrait scene set up by Sony at the press conference where the camera was announced. But once it found the humans behind both obstructions, it stuck with them.

The a6400—and other mirrorless cameras—have some tangible advantages over SLRs when it comes to autofocus. On a technical level, focus is acquired from the image sensor, so there's no need to calibrate a lens and body to ensure dead-on focus. From a usability standpoint, the focus area on a mirrorless camera is typically much wider than that of an SLR. When you pick up a good midrange SLR, like theCanon T7i, you see the focus points grouped toward the center of the frame in the viewfinder. If your subject falls outside that area, autofocus isn't going to pick it up. The a6400 has a dense mix of contrast and phase detection focus sensors, running almost to the edge of the frame. So if you're trying to capture a tight shot of a dog grabbing a frisbee out of the air, but aren't quite speedy enough to move the camera to keep up with a flying puppy, you'll appreciate that it can still find the subject when it's almost exited the frame.

The a6400 is fast—at its fastest it manages an 11fps burst rate. Shooting at top speed can make it difficult to track a moving subject, so Sony also includes an 8fps mode that allows for preview of changes in the scene from shot to shot, so you can better pan the camera to keep a moving target in frame. It aced our continuous focus test, keeping every image in focus as it shot a target moving toward and away from the lens, without dropping below 11fps.

When you're shooting that quickly, the camera's buffer can fill up fast. The a6400 is able to keep its top speed for 46 Raw+JPG, 49 Raw, or 114 JPG shots. There is a signficant amount of time required to clear the buffer to memory—41.7 seconds for Raw+JPG, 26.7 seconds for Raw, and 41 seconds for JPG. Our tests are done with a 300MBps memory card, but because the a6400 only supports UHS-I speeds, it's not taking full advantage of the latest, fastest media.

You can start shooting again while the buffer is partially cleared, but you can't do other things. If you want to start a video clip after shooting a burst of images, you're out of luck—the camera displays a message indicating that it's unable to start recording until all files have written to the card. This is a pain point I'd like to see Sony address in the future, but one big step would be supporting UHS-II transfer speeds.

Image Quality

The a6400 uses a 24MP APS-C image sensor, the same size and resolution as the a6300. It can be set as low as ISO 100 and as high as ISO 32000 in its native mode, and offers expanded ISO up to 102400 for those times when the light is very dim.

In the lab, Imatest reports that the a6400 keeps noise under 1.5 percent through ISO 3200 when capturing JPGs at default settings, and shows about 1.6 percent at ISO 6400—just outside our threshold of acceptable noise. Some cameras achieve low noise scores via aggressive noise reduction—which washes away detail along with grain—but the a6400's JPG output competes with full-frame models when shot through ISO 6400.

A close look at photos from our test scene shows that there's almost no loss of clarity from ISO 100 through ISO 3200. There is a very slight drop in quality at ISO 6400, but you'll have to look very closely to see it. It's at ISO 12800 where images start to suffer—details are noticeably smudged. The smudging gives way to blur at ISO 25600, and at the top ISO 51200 and ISO 102400 settings are blurry to the point they appear slightly defocused. It is at these extreme settings where full-frame models pull away from cameras with APS-C image sensors.

Shutterbugs will likely opt for Raw capture. I converted our Raw test images using Adobe Lightroom Classic CC with default develop settings applied. At lower settings there's not much difference in detail between JPGs and Raw images—Lightroom's default output even appears a little bit less sharp, but a slight bump in contrast will satisfy photographers who prefer a punchier look to images.

Raw images give you a lot more flexibility when it comes to adjusting exposure, pulling details from the shadows, or curbing too-bright highlights than any JPG. They also show more detail—and more grain—at higher ISOs. The a6400's Raw output doesn't lose any detail at ISO 6400, but does show a bit more grain than the corresponding JPG.

The difference between JPG and Raw output at ISO 12800 is night and day. The Raw image is certainly noisy, but the Raw file shows sharper, clearer details, where the JPG smudges them in order to wipe away the grain. The story is similar at ISO 25600, although results are a little rougher. Grain starts to overpower the image at ISO 51200 and 102400, though I'd feel comfortable using ISO 51200 for images that call for a rough look or a gritty black-and-white conversion.

4K Video

The a6400 offers a lot for videographers. It can shoot in 4K at up to 24, 25, or 30fps, and also supports 1080p capture at up to 120fps. Autofocus is solid, and you can set the focus rack speeds to suit your subject.

4K quality is lovely—sharp, colorful, and with the pop you expect from high-resolution video. Pros can move beyond basic settings and shoot Hybrid Log Gamma (HLG) HDR video, or opt for a flat S-Log2 or S-Log3 profile to get the most color grading latitude. Other pro features, including proxy recording to speed up 4K editing, are also included.

The flip-up screen just screams vlogging, but doesn't do you much good if you rely on an on-camera shotgun microphone for audio. There are third-party brackets available to move the mic to the side and alleviate the issue, but Sony could have made things a bit easier and used a screen that flips out to the side instead.

The lack of in-body stabilization is felt more on the video level than for stills. Sony's Optical Steady Shot stabilization, which is included in many of its native E-mount lenses, works well for stills, but doesn't stabilize moving images as well as a camera that leverages both in-body and in-lens tech.

A Exemplary Midrange Option

The a6400 definitely isn't entry-level—not when you can buy a basic Nikon D3500 SLR, with a lens, for five hundred bucks—and it's not top-end either. But if your needs are beyond basic, and you don't want to spend much more than $1,000 on a kit, it's a very appealing option.

There's a lot under its hood. Fast focus, improved by machine learning, a 24MP image sensor, and 4K video are just the highlights. It's also quite compact—even the 18-135mm kit zoom is small, considering its coverage range—so you don't have to think too hard about picking it up to take with you for a trip, whether it be to the local park or to Machu Picchu.

It's also not perfect. Sony has put real effort into improving its menu system, but I think there's some more room for refinement. It's a small thing, but I would have liked to see Sony include a wall charger for the battery in the box, and move to a more modern USB-C port for potentially quicker in-camera charging. Until Sony figures out a way around it, the frustration of not being able to record a video while images write to the memory card is something I consider to be a real pain point for anyone who wants to capture a mix of still images and video, and putting a UHS-II slot in the camera could also help.

And yes, the lack of IBIS is a downer, but there's no doubt that the camera is less expensive to produce without it. The a6500 is all but certain to be upgraded in the future, and its successor will likely carry a price above $1,000, along with a stabilized image sensor. It's a feature reserved for pricier mirrorless models. There are SLRs and mirrorless cameras with smaller Micro Four Thirds imagers with IBIS in this price range, but they aren't competitive with the a6400 when it comes to autofocus, which is the best we've seen in a camera under $1,000.

The brand new Fujifilm X-T30 promises to be nearly as good for about the same price. It omits weather protection, but enthusiasts may prefer its more intriguing lens library, film simulation options, and dial-based control system. We've not had a chance to full evaluate the X-T30—Fujifilm says we can expect a production sample to test soon.

The Sony a6400 isn't an absolutely perfect camera, but its flaws are more foibles than deal breakers, so we're naming it our Editors' Choice. It's the rare camera that serves both consumer and enthusiast audiences. Family historians will appreciate its speed, size, autofocus system, and image quality. Photographic hobbyists will be happy with more advanced features, like the subject tracking system, Raw image support, and 4K video resolution. Regardless of which group you're in, the a6400 is a stunning performer, especially when you consider its price.