Sony A7R IV Review

The Sony A7R IV is a top underwater camera boasting a 61 MP sensor, 10fps burst shooting, and excellent autofocus capability!
By Nirupam Nigam

Sony gets a lot of credit in the photography world for innovating. But the truth is….they deserve it. The release of the Sony A7R IV was a complete bombshell. On paper, it puts Sony solidly at the top of the mirrorless camera market and potentially as one of the best underwater cameras available. And if you already thought the Sony A7R III was a top camera, well the A7R IV is almost 20 megapixels ahead. 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. 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 ludicrous 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. 

By releasing the such a high resolution camera, Sony is beginning encroach on the realm of medium format photography – which hasn’t traditionally seen much attention by underwater photographers. But now that underwater photographers will have access to so much resolution, we can’t wait to see what they can do. Especially macro photographers who can crop to their hearts desire. And this camera isn't just for macro photography.  Its well-roundedness makes it perfect for macro, wide angle, supermacro, pelagic shooting, and pretty much any niche of underwater photography you can think of. 

Our team at UWPG was fortunate enough to receive a prototype Ikelite housing for the Sony A7R IV. So we decided to take the first ever underwater photos with the Sony A7R IV aboard the Socorro Vortex - the top liveaboard running trips to Guadalupe Island, Mexico - to go cage dive with great white sharks! After that we took the camera to dive with Blue Nation in Loreto, Mexico, and we're looking forward to taking it further south to La Paz for our annual photo workshop.


U.S. MSRP Sony A7R IV: $3500 

Available Now!


Sony A7R IV Underwater Review



Bluewater Photo Sony A7R IV Camera and Housings:

Sony A7R IV Camera

Ikelite Sony A7R IV Housing

Nauticam Sony A7R IV Housing

Aquatica Sony A7R IV Housing

Sea & Sea Sony A7R IV Housing 

Isotta Sony A7R IV Housing

Marelux A7R IV Housing



Jump To Section


Sony A7R IV vs Sony A7R III   |   Specifications   |   Key Features

Underwater Photo and Video   |   A7R IV Underwater Housings   |   A7R IV Underwater Lenses

A7R IV Sample Underwater Images   |   Conclusions




Sony a7r iv underwater review


Sony A7R IV vs Sony A7R III

The predecessor of the A7R IV, the Sony A7R III, is the most popular full frame camera for underwater photography. With R standing for resolution, 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 15 stops of dynamic range at low ISOs that was available on the A7R III, and in fact, the ISO range is the same. In our tests, we found that the dynamic range performance on the A7R IV did not appear to be hindered by the high resolution. This can be seen in the shark photos featuring beautiful gradients between the light rays going through the water and the shadowy blue water. However, it is important to note that we did notice more noise in photos with the A7R IV, even at lower ISOs. This is expected because adding megapixels to a sensor without increasing the sensor size results in smaller pixels and more noise. Fortunately, anytime you have finer megapixels, it's easier to remove noise in post processing. Another nice feature, though not for underwater photography, is the pixel shift feature which has been updated to create 240 MP photos. The EVF (electronic viewfinder) has been updated with higher resolution to 5.7M dots.

Autofocus on the A7R IV has actually been improved quite a bit, 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. We found that the autofocus on the A7R IV was much quicker underwater than the A7R III. In fact, if you shoot fast moving subjects and rely on autofocus tracking, it might be worth switching to the A7R IV. 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


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 Key Features

Body, Build, and Ergonomics

The Sony A7R IV is a solid camera and arguably an ergonomic improvement from the A7R III. The handgrip has been redesigned to feel “grippier.” For the most part, controls are unchanged from the A7R III so any Sony photographers looking to upgrade will be in a good place to do so. 

The biggest improvement 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 work in extreme environments, often with low visibility, the more resolution the better. Battery life is the same as the A7R III with about 530 images per charge – that’s honestly quite a bit better than competitors. Because of the size of the uncompressed RAW files, we actually found that we ran out of space on our cards before running out of battery life. Even after spending 8 hours a day in a shark cage, we only used one battery per day. However, sharks swim by infrequently, and the camera conserves battery really well while sleeping. We think a photographer can dive at least 4 dives per battery, if not more.

If you’re picky about dual card slots, well this camera has them – two UHS-II slots. With such high resolution, you're going to need them.


Resolution and Image Quality

Usually we don’t include a full section specifically about the resolution, but in this case it’s warranted. The Sony A7R IV’s 61 megapixels is an astounding upgrade from the A7R III’s already substantial 42.4 MP. This will benefit some underwater photographers over others. 61 MP is enough resolution to crop anything you want and still have an amazing quality photo. Therefore macro photographers will benefit the most. However, the size of the files you end up working with is something to consider, as well as the fact that it may be hard to notice a difference in resolution unless the camera is kept very still – something difficult to do underwater. That being said, 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 in the A7R III.

Motion blur is compounded at higher resolution. For this reason, we found that our macro photographs benefited most from the A7R IV. It's important to freeze the frame at a high shutter speed and shoot a slow moving subject. 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.

High resolution sensors also tend to take photos that are noisier than lower resolution counterparts because more pixels need to fit on the same sized sensor. This can even be true at lower ISOs. Fortunately, the noise can be easily removed in post processing because the grain of the noise is really fine.

Any underwater photographer considering this camera will need to weigh the benefit of having higher resolution photos and using storage space. After three days in a cage, we had about 300 GB in our hard drive full - with many uncompressed RAW files averaging about 130 MB in size.

The image quality on the Sony A7R IV can't really be compared to the Sony A7R III, Nikon D850, or Nikon Z7 – the camera’s main competitors. For photos where the frame is frozen and without motion blur, the quality is better. For wide angle photos where subject are moving - you might not notice much of a difference.



Sony A7R IV 100% Crop Test

The A7R IV's 61 megapixel sensor does have the potential to unlock detail from photos previously unattainable by any modern full frame camera. For macro underwater photographers in particular, 61 MP of resolution presents the possibility creating photos with significant crops, but retaining resolution for large prints. The level of detail on full size images is nothing short of incredible. The following 100% crops of uncropped images show just how well the A7R IV performed:

Autofocus System

Sony is known for spearheading autofocus in cameras. Fortunately, the Sony A7R IV has all of Sony’s updated autofocus technology, and it's nothing short of spectacular. It was clear during our underwater tests that the A7R IV's autofocus system is far superior to the A7R III. In fact, better autofocus is almost a more compelling selling point than the resolution update. When we were shooting great white sharks in the cage, the autofocus tracking locked on every time and stayed with the shark. I never had to worry that the focus point would lock on to anything else and could focus my efforts on composition as the shark passed by. When shooting in burst modes, some frames didn't keep up with the shark's quick movements, but over all it's clear that this AF system is perhaps the best on the market.

I often prefer to use single AF when shooting macro photography to ensure that the focus is locked on before I recompose. Continuous AF runs the risk of having the wrong point in focus when you hit the shutter. However, with the Sony A7R IV I felt comfortable enough with the camera's ability to lock focus at the correct point, that I left the camera in continuous AF for most of the time. Being able to trust the autofocus system is a huge deal for an underwater photographer. It frees up your attention so that you can focus on more important aspects of the photography.

Overall, Sony’s AF tracking system is one of the quickest AF systems in the world topside, and a little slower underwater. This is partly due to the E-mount glass available for underwater photography more than anything else. 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. When the A7R III came out, it lagged behind other full frame cameras in underwater autofocus. AF upgrades to the A7R IV put it in line or surpassing rival cameras like the Nikon D850, Nikon Z7, or Canon EOS R


Video Capability

The video capabability of the Sony A7R IV is about as good as it was on the A7R III – which is excellent. Sony has added a 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, 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 release 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 generally means more versatility...under the right conditions. Anyone shooting with 61 megapixels will be able to crop an image quite a bit and still maintain professional resolution. Details are crisper as long as the frame is frozen and there is no motion blur. The main concern we have with this camera is the level of stabilization required to reap these benefits. That isn’t to say there will be motion blur in photos, but it’s just that it’s possible that details will be a little blurred if you’re pixel peeping. There is also the concern for increased noise, even at lower ISOs, at such as high megapixel count. However, the noise is fine-grained and easy to remove in post-processing. Sony has maintained 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 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 large, 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 something quick like switch to DX mode


As there have been few changes to controls, the Sony A7R IV will be a great camera for anyone who already shoots Sony. However, there are substantial improvements with the electronic viewfinder that rivals the Pansonic S1 and S1H with 5.7 million dots and an excellent refresh rate. These improvements pushed the electronic viewfinder's performance past leading cameras like the Nikon Z7, especially when it comes to dynamic range. Electronic viewfinders have improved over the years, but they don’t perform quite as well as optical viewfinders. For underwater photographers this can be frustrating when shooting in situation with high dynamic range, like sunballs.

Above water the A7R IV has one of the quickest AF systems in the world, and underwater the A7R IV performs much better than the A7R III. Personally, I would upgrade to the A7R IV just for the improved autofocus and AF tracking. Whether it was 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) - but this is fine in most circumstances. If it does get too dark, the camera performs great with a focus light. Overall, any underwater photographer is likely going to be quite happy with this camera’s autofocus performance. 

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. 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 is improved from the A7R III. 


Sony A7R IV Underwater Housings

Most major underwater housing manufacturers are producing housings for the A7R IV including high quality aluminum housings from Nauticam, Marelux, Sea & Sea, Aquatica and Isotta, as well as a nice polycarbonate housing from Ikelite. So far, Ikelite and Nauticam have released their housings, and we've already had lots of experience with them!


Be sure to keep checking our Sony A7R IV underwater housing pages for updates on housings by major underwater brands: 

Nauticam Sony A7R IV Underwater Housing

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.

Marelux A7R IV underwater housing

Marelux Sony A7R IV Underwater Housing

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.


Ikelite Sony A7R IV Underwater Housing

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 Sony A7R IV Underwater Housing

Aquatica produces high-quality aluminum housings milled from a single aluminum block. They are robust, sturdy, and feature great ergonomics.


Sea & Sea Sony A7R IV Underwater Housing

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 conditions.


Isotta Sony A7R IV Underwater Housing

Isotta is known for their high quality aluminum housings and their Isotta Sony A7R IV Underwater Housing is certainly no exception. We love the Isotta A7R IV housing because it is one of the most light-weight and compact underwater housings for the A7R IV on the market. The built-in, curved handles are suprisingly ergonomic and very comfortable. And of course, we love the flashy red color that is characteristic of Isotta housings. If you want a cutting-edge, high-end, and unique tool to take your A7R IV underwater, then this is the one. 

Best Lenses for Underwater Use with the Sony A7R IV

Recent releases of lenses for the Sony A7 series has made the repertoire of underwater lenses much more versatile. 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 lenscan 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. 

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 F2.8 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.


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.


Lenses for Underwater Video

When in Super 35 mode we recommend the Sony 16-35mm F4 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 from the Sony A7R IV


The Underwater Photography Guide was fortunate enough to have the opportunity to take the first underwater images with the Sony A7R IV after receiving a prototype housing from Ikelite! Below are some photos taken while cage diving with great white sharks aboard the Socorro Vortex as well as some photos from reef diving in Loreto, Mexico with Blue Nation








The Sony A7R IV is not your traditional camera upgrade – it’s a true industry gamechanger. 61 MP has never been seen before in a full-frame camera. We're already extremely impressed with our underwater results. This camera is going to be like a microscope for macro photographers. With so much cropping ability, it’s going to be 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. The A7R IV's updated AF system unlocks it's extreme resolution by capturing accurate focus in almost any lighting situation. But most importantly, we found this to be a camera that takes all around amazing underwater photos and allows you to expand your creative abilities with features like AF tracking, a high resolution crop mode, 10 fps burst, and a good sized buffer. With so much resolution officially on the market, we can’t wait to see the next direction the world of photography is going to take. 




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Nirupam Nigam is the Editor-in-Chief of the Underwater Photography Guide and the President of Bluewater Photo - the world's top underwater photo & video retailer. While growing up in Los Angeles he fell in love with the ocean and pursued underwater photography in the local Channel Islands. After receiving degrees in Aquatic and Fisheries Science and General Biology, as well as a minor in Arctic Studies, Nirupam worked as a fisheries observer on vessels in the Bering Sea and North Pacific. Since then, Nirupam has been a full time underwater photographer and photo gear head. Check out more of his photography at!


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