Sony A7R IV Underwater Review
October 1st, 2019
Sony A7R IV Underwater Review
Sony is known for being an innovator. And the truth is….they deserve it. The release of the Sony A7R IV is a testament to this fact. The A7R IV is no minor upgrade and it puts Sony at the top of the mirrorless camera market and potentially as one of the best underwater cameras available. And if you thought the Sony A7R III was already a top camera, well the A7R IV is almost 20 megapixels more advanced. The A7R IV features a 61 megapixel full-frame Exmor R CMOS sensor – the most megapixels of any mirrorless camera to date. And the specs don’t stop there. Despite huge file sizes, the A7R IV can still accomplish 10fps continuous shooting (7 second buffer), real-time AF tracking in video, and a Pixel Shift Multi Shooting mode that can create 240 megapixel photographs. For those photographers that might be put off by the rediculous number of pixels – the A7R IV appears to be a fairly versatile camera with plenty of capability for day-to-day underwater shooting. This isn’t a camera that was just made for specifications. This was a camera made to be a photographer’s workhorse.
We think the Sony A7R IV is the mirrorless camera of the future, and certainly a top choice for underwater photographers. Now that underwater photographers will have access to so much resolution, we can’t wait to see the caliber of art produced in the next few years. Macro photographers will especially be able to crop to their hearts desire! The well-roundedness of this camera makes it perfect for macro, wide angle, supermacro, pelagic shooting, and pretty much any other type of underwater photography you can think of.
Our team at Bluewater Photo was fortunate enough to receive a prototype Ikelite A7R IV housing to use with our new Sony A7R IV camera. We decided to take the set up on our trip aboard the Socorro Vortex - a new liveaboard running luxury trips to Guadalupe Island, Mexico - to go cage diving with great white sharks. After some spectacular underwater moments, we can safely say that the A7R IV is the camera of the year!
U.S. MSRP Sony A7R IV: $3500
One of the world's first underwater photos with the Sony A7R IV. Taken with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and the Sony 16-35mm rectilinear wide lens aboard the Socorro Vortex liveaboard. 1/250, f/10, ISO 320
Comparison | Specifications | Features
Underwater Photo and Video | Lens Recommendation | Underwater Housings |
Sample Images | Final Thoughts
Sony A7R IV vs Sony A7R III
The Sony A7R III has is still one of the top cameras on the market for underwater photography. R means resolution. So of course the main upgrade to the A7R IV is a new 61 MP sensor from the A7R III’s 42.4 MP sensor. Sony is claiming that the A7R IV will maintain the same 15 stops of dynamic range at low ISOs that was available on the A7R III, and the ISO range is the same. We found that this was generally true in our underwater tests. Another nice feature, though not for underwater photography, is that the pixel shift feature has been updated to create 240 MP photos. Autofocus has improved on the A7R IV, which will be welcomed by underwater photographers. The A7R IV has almost 200 more phase detection focal points, covering 74% of the width and 99% of the height of the sensor’s surface. Both cameras still have a low light sensitivity of -3EV (@f/2). The AF system has been updated and includes touch tracking AF like on the a6400, as well as Eye AF in movie recording mode. When we took the A7R IV underwater, we could confirm that the autofocus system is lightyear's ahead of the A7R III! The EVF (electronic viewfinder) has been updated with higher resolution to 5.7M dots. So overall, I think it’s safe to say that the Sony A7R IV is an all-around better camera than the A7R III with an emphasis on resolution.
Sony A7R IV Camera Specifications
Key Upgrades from the A7R III
• 61 megapixel full frame Exmor R BSI CMOS Sensor vs 42.4 MP sensor in the A7R III
• Updated BONZX Image Processor
• Updated pixel shift feature can now combine 16 still photos to produce a 240 MP photo
• Improved autofocus capability – phase detection point coverage, and updated AF sytem including touch AF tracking and Eye AF in movie mode
• Eye Animal AF Tracking
• Updated EVF – now 5.7 M dots
• New Multi Interface Shoe (MI Shoe) – designed for audio
A tiny blenny stands out with detail that only a 61 megapixel camera could capture. Taken with the Sony A7R IV, Ikelite A7R IV housing, dual Ikelite DS 161 strobes, the Sony 90mm macro lens, and the Bluewater +7 diopter. 1/250, f/11, ISO 200
Sony A7R IV Complete Specs
• 61.0 MP Exmor R CMOS Sensor
• BIONZX Image processor
• 567 phase detection AF points, 425 contract detection AF points
• Phase detection AF points cover 99% of the height of the sensor and 74% of the width
• Autofocus tracking system updated with touch tacking AF and Eye AF in movie mode
• New Eye Animal AF Tracking!
• -3 EV lowlight AF sensitivity (w/ f/2 lens @ ISO 100)
• ISO sensitivity of 100-32000
• 15 stops of dynamic range at low ISO
• 4K video @ 30P
• S-Log2/3 and Hybrid Log Gamma picture profiles supported for video
• 3.0 inch LCD with 1.4 M dots – adjustable with 107 degrees up and 41 degrees down
• Zebra stripes and peaking MF available
• 1/250s flash sync speed
• Electronic shutter for silent shooting
• 5-axis in-body image-stabilization
• Continuous shooting Hi+: 10fps, Hi: 8fps
• Compressed RAW buffer of 68 frames, uncompressed RAW buffer of 30 frames
• 530 shot battery life
• Dual card slots – UHS-II
• Bluetooth and WiFi capability for image transfer
• Size: 5 1/8” X 3 7/8” X 2 3/4 “
• Weight: 1lb 7.5 oz/665 g
Sony A7R IV Key Features
Body, Build, and Ergonomics
The Sony A7R IV is a solid camera and with slightly improved ergonomics from the A7R III. The handgrip has been redesigned and made deeper. For the most part, the controls are unchanged from the A7R III so any Sony photographers looking to upgrade won't have to adjust their shooting style all that much.
The biggest improvement in ergonomics for underwater photographers is the electronic viewfinder. It maintains its size and 0.78X magnification rating, but it has a higher resolution at 5.76 million dots. And for underwater photographers that operate in extreme environments, often with low visibility, the more resolution the better. Battery life is the same as in the A7R III with about 530 images per charge. This is quite a bit better than competing full-frame mirrorless systems. Because of the size of the uncompressed RAW files, we actually found out that we ran out of space on our cards before running out of battery! The battery on the A7R IV is about good for four dives of hard shooting - which is plenty if you ask us!
If you’re picky about dual card slots, well you're in luck – two UHS-II slots. With such high resolution, you're going to need them.
Resolution and Image Quality
The Sony A7R IV’s 61 megapixels is an astounding upgrade from the A7R III’s already substantial 42.4 MP. 61 MP is enough resolution to crop anything you want and still have an amazing quality photo. This is a serious improvement for macro photographers. However, the size of the files you end up working with is something to consider - you're going to need a good computer to process your files and a lot of storage space. In three days of photographing sharks heavily we managed to fill up about 500 gb of space. It's definitely somthing to think about!
We found that sometimes it was hard to notice the benefits of increased resolution on moving subjects. Because there are so many megapixels on this sensor, it's important to shoot at higher shutter speeds. Improved detail is going to be more apparent on still subjects. Because motion blur increases at higher resolution, we found that our macro photographs benefited most from the A7R IV. Although our photos of great white sharks had extremely high resolution, they lost some detail due to motion blur. Our macro photos produced higher quality 100% crops than our wide angle images.
The engineers at Sony did a great job in maintaining the same great ISO sensitivity, dynamic range performance, and low light autofocus sensitivity as was available in the A7R III. Higher resolution sensors ten to take photos with a little more noise, even at lower ISOs. Fortunately, you can remove noise easily in post processing because the grain is very fine. Overall, we found the image quality to be better than the Sony A7R III, Nikon D850, and Nikon Z7 – the A7R IV’s main competitors. This was particularly true in photos where the frame is frozen and without motion blur.
Beautiful image quality and dynamic range produced by the Sony A7R IV. Taken with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and Canon 8-15mm fisheye lens w/ metabones in Loreto, Mexico. 1/160, f/18, ISO 200
Sony A7R IV 100% Crop Test
The only way to truly understand the value of 61 megapixels of resolution is to "pixel peep." With other cameras, pixel peeping can make you feel like you have a bad camera. But with the A7R IV, it brings out details that could not be captured with any other full frame camera. Macro photographers, in particular, can really benefit from 61 megapixels of resolution. Cropping lets you "recompose" your photo in post processing as well as bring out details beyond what your camera could capture with normal composition. Sometimes cropping is the only way to create a photo of an extremely small subject. Here are some 100% crops of macro photographs captured with the A7R IV, that show just how truly amazing 61 megapixels is. Be sure to click on each photo to view them in a larger size.
Autofocus System
Sony is known industry-leading autofocus capability. The Sony A7R IV has all of Sony’s updated autofocus technology which is nothing short of spectacular. We found that the A7R IV's autofocus system is far superior to that of the A7R III during our underwater tests. In fact, having this improved AF system is almost a more compelling selling point than the resolution update. When we shot great white sharks in the cage, the AF tracking system locked on focus every time and stayed wit hthe shark. We never had to worry that the focus point would lock on to anything else and all our efforts could be shifted to compostiion. When shooting in burst modes, some frames didn't keep up with quick movements, but it's clear that the AF system is one of the best on the market.
I often prefer to shoot in single AF, especially when shooting macro photos. However, the continuous AF system was so accurate that I was ok with letting the camera keep track of the AF point while I composed the shot instead of my usual "lock and pan" in single AF. Being able to trust the AF system is a big deal for an underwater photography as it frees up attention for focus on other, more important, aspects of photography.
Nudibranchs may be slow but quick autofocus is a huge help when the current is high. Taken with the Sony A7R IV, Ikelite A7R IV housing, dual Ikelite DS 161 strobes, the Sony 90mm macro lens, and the Bluewater +7 diopter. 1/250, f/14, ISO 200
Sony’s AF tracking system is one of the quickest AF systems in the world topside. The A7R IV is being used to also introduce Eye AF in movie mode and touch tracking AF – both won’t have much use in underwater photography.
Autofocus sensitivity in lowlight is still -3 EV (w/ f/2 lens @ ISO 100). This is pretty great considering the upgrade in megapixels. Although the lowlight AF performance could be improved a bit, it is certainly in line with the Nikon D850, Nikon Z7, or Canon EOS R - and better than the A7R III.
A quick and intelligent AF system is perfrect for capturing quick subjects. Taken with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and Canon 8-15mm fisheye lens w/ metabones adaptor aboard the Socorro Vortex liveaboard. 1/125, f/7.1, ISO 100
Video Capability
The video capability of the Sony A7R IV is about as good as it was on the A7R III – which is excellent. Sony has added an Eye AF feature, but that isn’t useful for underwater video. The A7R IV can shoot 4K @ 30p with S-Log2/3, and hybrid log gamma picture profiles available. The 4K quality is excellent on the A7R IV as it is downsampled from 6K – increasing the amount of detail in the image. Given these stats and the video quality, we expect underwater video shooters to be choosing between the Nikon Z6, Sony A7R III, and Sony A7R IV – at least until the Sony A7S III comes out.
Our initial sample video includes footage taken during our shark dives with the camera off the coast of Guadalupe Island, Mexico. It is slightly compressed to to the lack of processing resources we have in the field, and we cant wait to come out with a full video soon!
Sony A7R IV for Underwater Photography and Underwater Video
With the Sony A7R IV, the implication for underwater photography are obvious. More megapixels means more versatility as long as there’s no compromise in image quality and performance. Anyone shooting with 61 megapixels will be able to crop an image quite a bit and still produce a high-quality, printable image. Image details will be crisper which is great for all underwater photographers. One of our main concerns with the camera is increased noise, even at lower ISOs, given the high megapixel count. However, the noise is fine-grained and easy to remove in post-processing. Sony has created a decent image buffer with 10fps continuous shooting – a really amazing capability considering the size of the images.* Underwater photographers focusing on quick subjects and pelagic creatures might actually benefit quite a bit from this camera as they will finally have extreme resolution without compromising too much on burst speeds.
*It's important to note that while the buffer is relatively large fo the file sizes, some buttons are inoperable on the camera while the camera is writing to the card. We found this could affect a sequence of photos if we wanted to do a quick change in the middle like switch to DX mode
A shark and fish captured in burst mode. Taken with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and the Sony 16-35mm rectilinear wide lens aboard the Socorro Vortex liveaboard. 1/250, f/7.1, ISO 500
In terms of improvements in build and ergonomics, the Sony A7R IV will be easily adapted by anyone who shoots Sony and pretty intuitive even if you don't. There are substantial improvements with the electronic viewfinder that rival the Pansonic S1 and S1H with 5.7 million dots and an excellent refresh rate. We hope that these improvements push electronic viewfinder capability past leading cameras like the Nikon Z7, especially when it comes to dynamic range in the viewfinder.
Above water the A7R IV has one of the quickest AF systems in the world, and underwater it performs much better than the A7R III. Personally, I would upgrade to the A7R IV just for the benefits of improved AF and AF tracking. Whether it's sharks or macro subjects, I felt confident tracking anything that moved. Lowlight autofocus capability hasn’t changed since the Sony A7R III and is still -3EV (w/ f/2 lens @ ISO 100). This is excellent considering that low light AF often suffers after a resolution upgrade. Overall, any underwater photographer is likely going to be quite happy with this camera’s autofocus performance.
Beautiful details of soft coral polyps captured with the Sony A7R IV. Taken with the Sony A7R IV, Ikelite A7R IV housing, dual Ikelite DS 161 strobes, the Sony 90mm macro lens, and the Bluewater +7 diopter. 1/250, f/10, ISO 200
For underwater video, the Sony A7R IV is one of the top cameras on the market, but it won’t be much of an upgrade from the Sony A7R III. So if you’re an underwater videographer, I would look at the Sony A7R III or A7S II in order to save money. The Nikon Z6 and Panasonic S1 are also great full frame mirrorless options for video. Otherwise, any photographer who has the A7R IV will have access to industry-leading 4K video. 4K video still can be shot up to 30 fps, and it is down sampled from 6K for beautiful details underwater. Underwater autofocus in video works better than the A7R III.
Shark at golden hour. Taken with the Ikelite A7R IV housing and the Canon 8-15mm fisheye lens w/ metabones adaptor aboard the Socorro Vortex liveaboard. 1/320, f/22, ISO 100
Sony A7R IV Underwater Housings
Currently, Ikelite and Nauticam have excellent housing options for the Sony A7R IV. We also expect housings to be released from Aquatica, Sea & Sea, and Isotta:
The Nauticam A7R IV sets a high bar for underwater housings. Nauticam has always been known to produce top quality aluminum underwater housings and is designed to have great ergonomics. This housing is smaller than a standard dSLR housing, has an excellent port lock system, and supports a huge variety of lenses. The bulkheads support different combinations of sync cords, external monitors and/or their highly recommended vacuum valve system.
The Ikelite Sony A7R IV Underwater Housing brings affordability to a professional level, high end cameras. This robust and well built housing is a perfect way to get the quality and speed of the camera without tripling the cost of the system as with many aluminum housing options. We were extremely impressed with the first prototype Ikelite A7R IV housing we received. It had great buoyancy in the water and wasn't too negative. In fact, we didn't even find any need for floats with this housing! The controls allow for full functionality of the camera and there are a great variety of port options for the top underwater lenses for the A7R IV.
Aquatica produces high-quality aluminum housings milled from a single aluminum block. They are robust, sturdy, and feature great ergonomics.
The Sea & Sea Sony A7R IV housing is build from high quality aluminum. Ergonomics are excellent and buttons have luminescent labels to make them visible in low light condiditons.
Isotta is known for producing excellent aluminum housings with a characteristic red flaring. Bluewater Photo dubs them "the Ferarri of the Sea."
This Marelux underwater housing is built from high-grade aluminum alloy which provides durability and can withstand even the toughest beatings. Ergonomics are also top-notch, all camera controls are readily available at your fingertips and all buttons are clearly labeled. Thanks to its small size, it is great to travel with. Assembling the housing itself and installing a camera is a breeze with its quick release plate so you can spend more time under the water and less time setting up your gear. With a depth rating of 100m, this housing is an excellent option for both recreational divers as well as technical divers.
Best Lenses for Underwater Use with the Sony A7R IV
Recent releases of lenses for the Sony A7 have made the A7 cameras some of the most competitive in the market. Sony A7R IV users have an excellent set of choices for shooting macro, wide, mid-range, and fisheye.
Wide-Angle Lenses
The Sony 16-35mm F4 lens is the top wide-angle lens choice for photo and video. If you’re looking for something even wider to get nice close-focus wide-angle (CFWA) shots of reefs there are a couple of options for shooting fish-eye. The 28mm prime lens with a fisheye conversion lens will give the widest possible angle of view. The fisheye conversion lens can be used behind a large or small dome port, while the Sony 16-35 mm F4 les is recommended for use with an 8-inch dome or larger.
Wet wide-angle lenses are a great option with this camera. We recommend the Nauticam wet wide-angle lens or the Kraken KRL-01 wet wide-angle lens with the 28mm prime lens. All of these options are very sharp and will result in stunning wide-angle photos.
A yellow tail taken with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and the Sony 16-35mm rectilinear wide lens aboard the Socorro Vortex liveaboard. 1/250, f/11, ISO 500
Mid-Range Lenses
The Sony 24-70mm f/4 or the Sony 28-70mm F3.5-F5.6 are good choices along with the 35mm F/2.8 portrait lens.
Macro Lenses
For underwater photography, the Sony 90mm macro prime lens is the best choice for small fish and macro subjects. It is exceptionally sharp and produces high quality images. A 50mm macro lens is another great option, though it doesn't focus much quicker than the Sony 90mm.
The spectacular patterns of a flower sea urchin in the Sea of Cortez taken with the Sony A7R IV, Ikelite A7R IV housing, dual Ikelite DS 161 strobes, the Sony 90mm macro lens, and the Bluewater +7 diopter. 1/250, f/14, ISO 200
Canon Lenses
Canon lenses can be attached to the Sony A7R IV with the Metabones or Photodiox adapters, but auto-focus is generally better with Sony lenses. Lenses like the Canon 8-15mm, 16-35mm, and 17-40mm work well. The Canon 8-15mm fisheye lens is recommended when shooting video using Super 35 crop mode. You can also use the Canon 100mm lenses.
Sea Star photographed in the Sea of Cortez. Taken with the Ikelite A7R IV housing and the Canon 8-15mm fisheye lens w/ metabones adaptor in Loreto, Mexico. 1/160, f/11, ISO 200
Lenses for Underwater Video
When in Super 35 mode we recommend the Sony 16-35mm F/4 lens or the Canon 8-15mm fisheye lens. For closer shots use the Sony 24-70mm or the 28-70mm zoom lens.
Sample Underwater Images
We were lucky enough to take the first underwater images with the Sony A7R IV after receiving a prototype housing from Ikelite! Here are some shots we shot cage diving with great white sharks aboard the Socorro Vortex as well as some photos from reef diving in Loreto, Mexico.
Close-focus wide-angle shot of a moray eel with the Sony a7R IV, Ikelite A7R IV housing, and the Canon 8-15 mm fisheye lens w/ metabones adapter in Loreto, Mexico. 1/200, f/6.3, ISO 200
Sea star skin in the Sea of Cortez taken with the Sony A7R IV, Ikelite A7R IV housing, dual Ikelite DS 161 strobes, the Sony 90mm macro lens, and the Bluewater +7 diopter. 1/250, f/10, ISO 200
A great white shark taken with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and the Sony 16-35mm rectilinear wide lens aboard the Socorro Vortex liveaboard. 1/250, f/11, ISO 500
Coral in the Sea of Cortez taken with the Sony A7R IV, Ikelite A7R IV housing, dual Ikelite DS 161 strobes, the Sony 90mm macro lens, and the Bluewater +7 diopter. 1/250, f/10, ISO 200
A great white shark captured with the Ikelite A7R IV housing, dual Ikelite DS 161 strobes, and the Sony 16-35mm rectilinear wide lens aboard the Socorro Vortex liveaboard. 1/250, f/9, ISO 500
School of surgeonfish with the Sony a7R IV, Ikelite A7R IV housing, and the Canon 8-15 mm fisheye lens w/ metabones adapter in Loreto, Mexico. 1/160, f/13, ISO 200
Final Thoughts
The Sony A7R IV is a gamechanger. 61 MP has never been seen before in a full-frame camera. In fact, the A7R IV is already being called a "psuedo-medium format camera." Since medium format has largely been ignored by underwater photographers, we expect to start seeing some truly spectacular, high resolution underwater photography when the A7R IV comes out. This camera is going to be like a microscope for macro photographers. With so much cropping ability, it’s easy to highlight skin tones, photophores, and those gross little parasites every fish seems to have. Even wide-angle shooters are going be happy with 10fps and a 7 second buffer at that speed. After taking it underwater we can safely say that the Sony A7R IV is our top camera of 2019! With an upgrade like this, we can’t wait to see the next direction the world of photography is going to take.
We'd like to thank Pelagic Fleet and Blue Nation for helping make this review possible!
