Sony FX3: Initial Thoughts & Review

The Sony FX3 has the Same Amazing Underwater Video Capability as the Sony A7S III in an FX Cinema-Line Body
By Nirupam Nigam

The Sony A7S III was a bombshell camera release for many underwater video shooters. It's been our favorite camera in 2021 for underwater 4K video with a wide range of options for video workflows and post-processing. The Sony A7S III is a particularly capable camera in low light environments, easily capturing clean video at ISOs past 12,800.This makes it perfect for many underwater shooting situations. Shortly following the rollout of the A7S III, Sony announced the Sony FX3 - which is basically the Sony A7S III in a Sony cinema line body. So why did Sony release the same internals in a different body and what does this mean for underwater video shooters?

Sony FX3 Release Date: March 2021

U.S. MSRP: $3899




The staff at Bluewater Photo will be the first to know about any update in Sony FX3 housing! So be sure to contact them at for any information on new housings or to pre-order a Sony FX3 housing.



Sony FX3 vs Sony A7S III

When we say the Sony FX3 is exactly the same as the Sony A7S III internally, we mean it. They share essentially the same specs, video quality, recording options, etc. However, there have been some changes to the body of the FX3 that orient it for cinema shooters:

  • The Sony FX3 is slightly smaller than the Sony A7S III and lacks a viewfinder
  • The FX3 is sold with a detachable handle. The handle has twin XLR/TRS terminals. These are audio features, and obviously the handle won't be of much help underwater.
  • The FX3 has a zoom lever, but there are only two Sony lenses that will work with this lever - the FE PZ 28-135mm f.4 and the FE C 16-35mm T/3.1. The latter may be useful for underwater video but not the former. 
  • There are multiple tally lights that have been added to the body, so you never have to worry about knowing if the camera is recording. 
  • The Sony FX3 has a cooling fan which will extend recording times. However, overheating is not a huge issue with the Sony A7S III. However, we have had reports that at 4K/120p continuously filmed underwater for 20 minutes, the camera can over heat. So if you want to do a lot of slow motion filming, the FX3 might be a good option.
  • The FX3 body has thread holes for accessories
  • Price: The Sony FX3 clocks in at $3899 whereas the Sony A7S III is $3499. This is likely because of the included handle/XLR adapter


Should You Buy the Sony FX3 or the Sony A7S III?

Underwater, many of the differences between the Sony FX3 and the Sony A7S III become a moot point. The handle and XLR adapter and thread holes will not be useful to underwater shooters. It's specifically the handle that comes with the FX3 that contributes to the increase in price. However, the Sony FX3 could be a better camera overall for two reasons: 

  1.  The smaller form factor for the FX3 could result in smaller housings. Although this is result of the removal of the electronic viewfinder, most underwater video shooters choose not to use a magnified view finder when composing. However, we may not see a large difference between the two systems do to the same port requirements. 
  2. The Sony A7S III has been reported to overheat when shooting 4K/120p for extended periods underwater (20 minutes or greater). Although most people don't shoot at 120fps for long periods of time, there are some underwater situations where this could be useful if you have the storage capacity. So the addition of the cooling fan could be useful for these specific people. 


Will There be Sony FX3 Underwater Housings Available?

Will Sony FX3 Housings be Coming Soon?

Judging by the camera bodies, the Sony A7S III housings will not be compatible with the Sony FX3. As of yet, there have been no formal announcements from top housing manufacturers regarding a Sony FX3 housing. Because there are already Sony A7S III housings available, housing companies may be reticent to put more investment into R&D for Sony FX3 housings. The underwater camera sales department at Bluewater Photo will be some of the first to know of any housing releases, so make sure you contact them at for any information on new housings or to pre-order a Sony FX3 housing.




If you can't wait for a Sony FX3 housing, order a Sony A7S III underwater housing at Bluewater Photo:

Nauticam Sony A7S III Underwater Housing

Ikelite Sony A7S III Underwater Housing

Sea & Sea Sony A7S III Underwater Housing

Aquatica Sony A7S III Underwater Housing

Isotta Sony A7S III Underwater Housing


Order a Sony A7S III Camera Body at Bluewater Photo:

Sony A7S III Camera Body

Read Our Top Sony A7S III Underwater Settings

Check out our full Sony A7S III Underwater Housing Buyer's Guide


Contact Us for a Special Sony A7S III Underwater Package





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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