Sony a7S III Underwater Camera Review
A Mirrorless Camera Tailor-Made for Video The Sony a7S III camera looks and feels similar to other cameras in the a7 series, but under the hood, it is dramatically different. This camera was made for video shooters. The camera allows for shooting up to 4K 120p at 280mbps with 10-bit color in a 4:2:2 color space with no practical limitations for an underwater shooter as far as time limits or heat concerns. The lower resolution 12MP sensor won’t turn heads for photo shooters, though a 12MP image is great for social media and online use, and can scale up to a moderate size for printing. The excellent low light performance and video specs are what sets this camera apart. This macro demo reel was shot on location at Lembeh Resort by Backscatter Photo Pro James Emery with the Backscatter Macro Wide 4300, Backscatter Optical Snoot OS-1, Backscatter Color Filter System, and Sony a7S III Mirrorless Camera.While the Sony a7S III camera is mainly aimed at video shooters, the 12MP sensor still provides great detail and good image quality suitable for social media and online use. Sony a7S III | Sony 90mm Lens | Backscatter Mini Flash MF-1 | Backscatter Optical Snoot OS-1 | Backscatter Color Filter System | 1/250 | ISO 100 | ƒ22Combine the Sony a7S III Mirrorless Camera with creative tools like the Backscatter Macro Wide 4300, Backscatter Optical Snoot OS-1, Backscatter Color Filter System to create dramatic results.Sony a7S III | Sony 90mm Lens | Backscatter Macro Wide 4300 | Backscatter Optical Snoot OS-1 | Backscatter Color Filter System | 1/250 | ISO 200 | ƒ22Practical Real World Use Video Specs This is first and foremost a video-oriented camera. The lower resolution of the 12MP sensor allows for a faster readout, making rolling shutter practically a non-issue for scenes with faster moving subjects or fast camera pans. While it won’t shoot 5.9K 30p like the Panasonic S1H or 8K 30p like the Canon EOS R5, what everyone really wants is at least 4K 60p, with 4K 120p being the holy grail. The ability to shoot 4K 120p and slow it down to 1/2 speed in a 4K 60p timeline is the ultimate dream. And unlike the Canon EOS R5, there’s no overheating issues to overcome. 4K 120p and 60 can record up to 10 bit in a 4:2:2 color space, with 120p at a 280mbps and 60p at a 200mbps bit rate. These are specs for internal recording to a CFExpress Type A card, which is pretty incredible as these types of specs in the past required a large external recorder. With such a high bit rate and color depth, the files coming from the Sony a7S III have much more latitude in post for color grading and exposure adjustments than previous models. While this might not be an ideal scene to shoot, it serves as a good example of the low shadow noise with the Sony a7S III. Shooting a backlit scene in poor visibility leads to very bright backgrounds and underlit foregrounds. In this extreme test, we show the original clip straight from the camera showing shadows in the foreground that seemingly have no detail left. The second shot is the same clip as the original but with the shadows boosted in post. There’s plenty of detail in the shadows that can be recovered, with hardly any noticeable noise penalty.WHITE BALANCEMassively Improved—Finally On Par With Canon In the past, the weakest link in the Sony a7S series of cameras was the underwater white balance performance. Every other spec and feature of the camera was fantastic. However, none of that matters if the color isn't right, but this time Sony got the color right. Taking a manual white balance underwater in wide angle ambient light only conditions is the true test of any camera’s worth for use underwater. We tested underwater manual white balance in various conditions and depths and are very pleased to report that even in excess of 70 feet, the color still looks great. We see none of the magenta water that would creep in at about 45-50 feet with the Sony a7R IV. With 4 white balance banks and an easy to execute procedure, this camera is one of the top picks for all-around video use. We’re very pleased with the ambient light wide angle manual white balancing of the Sony a7S III. Even at depths exceeding 70 feet, the colors look fantastic. Previous Sony cameras and other poor performing custom white balance cameras typically render the water a magenta color, which is near impossible to fix in post. This is a major upgrade and makes the Sony a7S III a truly viable underwater video camera.S-LOG FOR GREATER DYNAMIC RANGE Sony has their own color profile called S-log that allows for more dynamic range in a shot. It works by basically changing the tone curve of the image that is captured on the sensor by boosting the shadows while preserving highlights. By boosting the shadows the lowest ISO becomes ISO 640. The result is a “flatter” image with less contrast that preserves more dynamic range detail, up to about 15 stops. Video shot in S-log must be color graded in post to get the best color and contrast. For most underwater shooting scenarios, just using a “normal” picture profile is really close to what the final edit will look like, and will be sufficient for most shooters without the need to do extra color grading work in post. S-log footage straight out of the camera looks a bit flat and uninspiring, but it preserves the greatest dynamic range available from the Sony a7S III. Color grading the footage in post gets the best results for turning a scene with poor visibility and color rendering in the standard picture profile to a more pleasing tone. Notice the detail of the surface waves at the top of the frame in this high dynamic range shot.CLEAR IMAGE ZOOMTurn a Fixed Length Lens Into A Zoom A great feature to make it easier to frame shots is the Clear Image Zoom feature. When activated the camera allows for a digital zoom up to a 1.5 crop of the sensor. While shooting it acts just like a zoom lever on a camcorder. This makes it super simple when set up on a macro critter on a tripod to activate a little zoom for a better composition rather than trying to move the whole tripod and risk not getting the shot. It can also be used to make a short sequence of medium then tight without losing depth of field or having to refocus. We’ve done something similar with the previous full-frame Sony cameras in video by switching to Super 35 mode for a tighter crop. There will be some controversy here as the 12MP sensor will dip below the actual 4K resolution specs when executing this zoom. The camera upscales the difference while still shooting in 4K. We couldn’t notice a dip in quality when looking at our own footage. Sony is using proprietary technology to scale in Clear Image Zoom, which results better than trying to do it in post. A limitation of Clear Image Zoom is that the camera can’t be set to RAW for still photos. Clear Image Zoom is like having a zoom button for a fixed focal length lens. It will allow for up to a 1.5 sensor crop worth of zoom, allowing more versatility in shots, and makes it easier to frame a subject without having to continuously move a tripod for perfect positioning on a moving subject. Sony Doesn’t Say It Has Dual Native ISO, But It Behaves Like It Does While there isn’t a spec on a dual native ISO feature from Sony, we can see it when changing from certain ISOs. When switching from ISO 1250 to ISO 1600, & ISO 10000 to ISO 12800 you can see the noise level drop a lot. This will allow for higher ISO shooting with greater dynamic range, and allow for the higher shutter speeds needed for a 180-degree shutter angle at 120 fps, making this one of the lowest noise cameras we’ve ever seen before. Where the crossover ISO happens will depend on which picture profile is selected, for example, normal vs. S-log. Whenever approaching the crossover point on the ISO, it’s preferable to shoot the higher cleaner ISO rather than the lower noisier ISO. While this might not be an ideal scene to shoot, it serves as a good example of low noise with the Sony a7S III. The first scene is shot at the extremely high ISO 10,000, then the same scene shot at the next higher ISO step at ISO 12,800 where the dual native ISO crosses over. The original straight from camera S-log clips shows a pretty significant drop in noise when the crossover happens. The clips are then both color graded to show the better dynamic range and lower noise benefit that can be had from shooting at the higher 12,800 ISO. HI-RES EVFMakes an External Monitor Optional The 9.44 dot electronic viewfinder (EVF) is one of the highest resolution EVF’s out there. This makes it easy to see critical focus even without focus peaking turned on. It can display a refresh rate of up to 120 times a second, making it the most realistic looking EVF we have seen to date out of any mirrorless camera. For those who still struggle with vision and critical sharpness, the focus peaking feature of the EVF is a must-have for those tight macro shots with limited depth of field. The image produced in the electronic viewfinder is one of the sharpest and most life-like that we’ve ever tested.Sony a7S III | Sony 90mm Lens | Backscatter Mini Flash MF-1 | Backscatter Optical Snoot OS-1 | Backscatter Color Filter System | 1/250 | ISO 200 | ƒ22 It might sound strange to recommend an EVF for shooting video. But in high ambient light conditions, or for seeing critical focus, the EVF provides a dark environment and easy to see view to make sure you nailed the shot. It was especially useful when paired with a 45 degree expanded viewfinder for macro shooting, making it easy to see the scene in bright ambient conditions while being able to see critical focus. Pro Tip: Remember to wear a black skirted dive mask when shooting so when looking through a viewfinder ambient light doesn’t reflect off the mask, making the viewfinder easier to see. AF PERFORMANCEGreat for Stills, Needs Menu Customization for Video The AF performance can be broken down into 2 different segments—movie and stills. The implementation is quite different. We’ll start with video then move into stills. While recording movies in macro, the focus tends to hunt as critters move in and out the very limited depth of field. This is understandable when shooting macro and we don’t consider this to be a fail of autofocus in this situation. It’s best just to lock the focus and let the scene happen. In wide angle, we can hear the focus motor and see the camera constantly updating autofocus. This can lead to some unwanted small focus hunts where it is making too many focus changes. Like in macro, we found it better to set up a scene and lock focus down rather than letting it track or update focus continuously. For moving subjects in the foreground, like a turtle, we suspect focusing and tracking on a critical area like the eye would yield good results, however, we haven’t come across that situation yet in our testing. Keep in mind that if the focus point falls of what the camera's tracking, there will be a focus change, which could ruin a shot. This is why we prefer to preset focus before shooting, maintain distance to subject, and use higher apertures for more depth of field in case of any camera to subject distance change. We might need more time to play around with the autofocus menu settings in video mode to see if we can tweak the AF speed and sensitivity to have smoother results when using continuous AF. For stills, this camera has the same focus system as the Sony a7R IV, which is fantastic. The “Real time tracking AF” is the only focus method that should ever be used for stills in this camera. It is similar to the 3D tracking focus system in the Nikon D850, our favorite autofocus tracking system implementation ever. Basically, it works like this: There’s a focusing square in the center of the screen that when pressing the AF-ON button will focus on the subject in the square, and as long as the AF-ON button is being pressed, the camera will track the movement of that subject through the frame and update focus continuously. Put the focus squarely on the eye of a subject either by moving the focus point around, or just move the camera to put the square over their eye, press and hold AF-ON, and it will track the eye of that subject. In the rare instance of the focus point slipping off the subject, just release the AF-ON button, repoint and engage again. Those familiar with the Nikon 3D tracking feature will find that it works exactly the same way. Using the technique allows the photographer to shift attention away from focusing and onto composition and framing, making it easier to get a lot more keeper shots. It will change your life and you’ll rarely ever have an out of focus shot again. The autofocus performance with real-time tracking AF for a photo is excellent.Sony a7S III | Sony 90mm Lens | Backscatter Mini Flash MF-1 | Backscatter Optical Snoot OS-1 | Backscatter Color Filter System | 1/250 | ISO 200 | ƒ18CONCLUSIONBest Choice for a Mirrorless Video Camera Sony clearly chose to make an all-out video camera with the Sony a7S III. The video specs of shooting up to 4K 120p with a lower resolution, faster readout, low noise, high dynamic range sensor on paper make this a great choice for a video camera. But in real-world performance, Sony has always fallen short, sometimes really short in earlier models, of being able to execute the most important task of a manual white balance underwater for wide angle ambient light scenes. As we have said many times before, a camera can have all the best specs in the world, but if the color is crap, nothing else matters. And now that problem is solved. Being able to capture 4K 120p at 280mbps with 10-bit color and a 4:2:2 color space in such a small package, and on top of that to an internal card, makes this a great run and gun camera for shooters who want top pro-level image quality, but want a relatively small package. In the past specs like this required a large external recorder or a much larger cinema camera. While it’s not necessary to have an external recorder some folks will still like to have an external monitor. Even without an external monitor, the camera's screen and super hi resolution EVF are all that’s needed to get in the water and start shooting. The quality of the footage in 4K will rival that coming from other 4K 60p full-frame capable cameras. While the Sony a7S III lacks being able to shoot 5.5K like the Canon 1DX III, 6K like the Panasonic S1H, or even the 8K of the Canon EOS R5, in the end, it doesn’t really matter. What everyone wants is a 4K 60p timeline with the ability to shoot 4K 120p and slow it down. There’s no overheating issues like the nearest competitor to this camera, the Canon EOS R5 has in 8K or 4K 120p. If you already own Canon glass, the Sigma MC-11 mount converter allows you to use Canon lenses on the Sony body if one was so inclined. The next time we need to shoot some video, the Sony a7S III is at the top of our list for its small size, killer video specs, and excellent ambient light white balance underwater. ProsFinally, an underwater white balance Sony can be proud ofTop level 4K 120p 4:2:2 10 bit color, no external recorder neededExcellent low noise performanceGreat dynamic rangeSame great Autofocus for stills as the Sony a7R IVNothing holding this camera back from being someone’s top choice for an underwater video rigCons12MP resolution is a great sensor for video, but not enough pixels to be a true photo cameraBetter off to lock focus in movie mode due to constant AF updatesWhy buy direct from Backscatter?Free lifetime tech support with every purchase. We will beat any advertised price. Free shipping to USA and Canada and low-cost international shipping. ABOUT THIS ARTICLE The test footage and still images from this review were shot in Lembeh and Mando, Indonesia by our in-house Backscatter Photo Pro at Lembeh Resort, James Emery. Lembeh Resort is one of the top destinations in the world for underwater macro photography. The team at the Backscatter Photo Center at Lembeh Resort can get you set up with classes, private guided photo dives, and help with off camera lighting on your dive. Contact Dan Baldocchi at Underexposures to book a trip to Lembeh Resort and get your macro shooting skills dialed in with a class, or a private guided dive to get the best shots Lembeh has to offer. CAMERA & HOUSINGSSony a7S III Camera $3,499.99ORDER NOWAquatica Sony a7S III HousingORDER NOWIkelite Sony a1 and a7S III HousingORDER NOWIsotta Sony a7S III HousingORDER NOWNauticam NA-a1 HosuingORDER NOWNauticam NA-A7SIII HosuingORDER NOW Sea & Sea MDX-α7SIIIU HousingORDER NOWSeacam Sony a7S IIIHousingORDER NOW