Sony a6400 Announced!

Sony introduces its next mirrorless Alpha line camera - the a6400
By Nirupam Nigam

Sony has recently announced its newest model of Alpha line APS-C (crop sensor) mirrorless camera – the Sony a6400. The name might cause a little confusion as the Sony a6400 is actually the next camera in line after the Sony a6300 and Sony a6500. However, an in depth look at the specs indicates that the a6400 is more of an upgrade to the a6300 than the a6500 – so the name makes sense.

Among Sony’s wide range of mirrorless systems, the a6400 is a great option for photographers looking to take high-quality photos with high-quality lenses but desire a lighter price point and a more compact system. Being an APS-C mirrorless camera, the a6400 is significantly smaller and cheaper than the popular full-frame mirrorless Sony A7R III. As an E-mount camera, the a6400 is compatible with all the excellent lenses currently available to other E-mount systems such as the a7, a9, and NEX series.

U.S. Retail Price: $899 (for the body only) – Available February, 2019


Purchase the Sony a6400 at Bluewater Photo



Jump to section:

Key Features     |     Upgrades from the a6300    |    For Underwater Photography    |    For Underwater Video

Best Lenses    |    Underwater Housings    |    Conclusion    |   Underwater Photos


Sony a6400 Key Features 

  • 24.2 MP APS-C Exmor CMOS Sensor

  • Latest BIONZ X Processor

  • Lightning quick autofocus acquisition of 0.02 sec

  • 425 phase detection contrast-detection AF points covering approximately 84% of image area

  • Real-time Tracking for object tracking

  • High-speed continuous shooting at up to 11 fps

  • Improved buffer size for JPEG and RAW

  • Advanced High-Resolution 4K with Fast Hybrid Autofocus

  • Interval recording for time-lapse videos

  • 180-degree fully tiltable LCD touch screen

* View the full details for each of these highlights on the Sony a6400 website.


Sony a6400 Upgrades from the Sony a6300

  • More of a “sports oriented” focus system – better real-time autofocus tracking and better eye detection autofocus

  • Better low-light autofocus – working range of EV -2 to 20 (expanded from -1 to 20)

  • New-generation BONZ X processor

  • Upper ISO limit increased from a default of ISO 25,600 to ISO 32,000

  • Buffer capacity almost doubled – Sony claims 99 extra fine JPEGs, 46 raw files, or 44 raw+JPEG

  • Support for HD proxy video recording 

  • Can now shoot video with Hybrid Log Gamma (HLG), S-Log2, or S-Log 3 picture profiles for HDR-ready footage

  • Loss of MP4 file format for video shooters – only XAVCS and AVCHD formats available

  • 180-degree fully tiltable LCD touch screen – great for vlogging (screen flips up, not to side)

Sony a6400 for Underwater Photography

The Sony a6400 is a solid upgrade from the Sony a6300; Each upgrade will have a different implication for underwater photography. With improvements in real-time autofocus tracking, image processing, and buffer capacity, it is clear that Sony intended to build-up the a6400’s “sports photography” capability. This will come as a godsend to any underwater photographer that specializes in shooting large, quick pelagic animals. The better low-light autofocus is an overall improvement that benefit all underwater photographers – especially those shooting in cold-water, low-light conditions. 

Despite these upgrades, there are some real benefits to shooting the Sony a6500 over the a6400. The a6500 has built-in image stabilization (IS) that is not available in the a6400. Built-in IS can significantly improves image quality when taking photos underwater in a 3D environment with a lot of movement. The a6500 also has better support in its housings for external battery packs. The a6300’s batter life is good for a mirrorless camera at 350-400 shots, but not as good as a DSLR. It stands to reason that the a6400’s battery-life will be similar. It would be useful to have external battery packs in the housing so the battery would not need to be changed after every dive or every other dive.


Sony a6400 for Underwater Video

The Sony a6400 is a good choice among mirrorless cameras for use in videography. The video capability is not very different from the a6300. The a6400 will be able to shoot up to 4k resolution at 30 frames per second with no pixel binning. 1080p can be shot up to 120fps – great for quick action video. The biggest upgrade will make HDR shooters happy – the a6400 can now shoot video with Hybrid Log Gamma (HLG), S-Log2, or S-Log 3 picture profiles. HD proxy video recording is also a new feature that enables videographers to capture lower quality footage for streamlined editing and replace it with full resolution footage during rendering. It is important to note that the a6400 will no longer support an MP4 file format – only XAVCS and AVCHD.


Sony a6400 Best Lenses


Standard / Mid-Range



Sony a6400 Underwater Housings

A wide range of housing options for the a6400 will be available from most major underwater housing manufacturers. Housings will likely be available from Aquatica, Fantasea, Ikelite, and Nauticam. Natuicam offers the top-of-the-line and most ergonomic option - often coming at a price. Fantasea and Aquatica make solid mid-range options. Ikelite is an excellent choice for photographers looking for a budget housing.  


The Sony a6400 will likely not be compatible with the a6300 or a6500 housings due to differences in body size. 



As with the a6300 and a6500 before it, the Sony a6400 will likely be an excellent APS-C mirrorless camera - smaller than DSLR's and increasingly popular full-frame mirrorless systems, but still yielding excellent image quality and focus speeds. Sony E-mount lenses are becoming more versatile and increasingly excellent in their image quality. If you want most of the quality found in Sony a7 systems but balk at the size and price tag then the Sony a6400 is for you.

Should you upgrade from the Sony a6300? That could go either way. If you tend to shoot large and quick pelagic animals requiring a large buffer and quick focus tracking, then yes - an upgrade is a good idea. However, if you are looking for an all around improvement in image quality, battery life, and video, you still may want to take a look at the Sony a6500 over the Sony a6400. 

Standing alone the Sony a6400 packs a powerful punch. With lightning fast focus, upgraded processing, support for hybrid log gamma, 425 auto-focus points, Sony E-mount lenses, and 24 MP - you really can't go wrong whether you're taking underwater photo or video.


Underwater Photos

Because the Sony a6400 has not yet been released for testing, here are some photos from the Sony a6300 and Sony a6500 for comparison:

Sony a6300

Sony a6500



Nirupam Nigam is a dedicated underwater photographer and fisheries scientist. While growing up in Los Angeles he fell in love with the ocean and pursued underwater photography in the local Channel Islands. He received degrees in Aquatic and Fisheries Science and General Biology, as well as a minor in Arctic Studies, at the University of Washington. Now he works as a fisheries observer on boats in the Bering Sea and North Pacific. When he is not at sea, he is traveling with his fiancee and taking photos. Check out more of his photography at!


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