Sony A7 IV Underwater Camera Review

March 31st, 2022

The Sony A7 IV represents Sony's best value full-frame mirrorless camera, capable of capturing 33-megapixel photos and 4K/60p video. We had the fortunate opportunity of being the first to put this camera to the test underwater in the wild, shark-rich waters of the Revillagigedo Archipelago. While the lightning-quick autofocus, updated ergonomics, and extensive video options are incredible, we did discover some limitations to image quality and video.

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Sony A7 IV Camera Body

Ikelite Sony A7 IV Underwater Housing

Isotta Sony A7 IV Underwater Housing

Nauticam Sony A7 IV Underwater Housing

Aquatica Sony A7 IV Underwater Housing

Sea & Sea Sony A7 IV Underwater Housing

Marelux Sony A7 IV Underwater Housing

Sony A7 IV Underwater Housing Guide

Read our Top Sony A7 IV Underwater Settings

The Sony A7 IV Represents Excellent Value

With the supply chain crunch taking its toll on the industry, mid-tier camera production has slowed down and, in some cases, completely stalled. So when Sony announced the release of the Sony A7 IV, it came as a welcome surprise. Most manufacturers are focusing their production lines on high-end models, such as the Canon EOS R3 or the Nikon Z9, which both come in at over $6,000 just for the body.

Having a full-frame true photo/video hybrid option on the market at under half the price of the R3 or Z9 fills a gap in the current market. On top of that, there is a wide range of affordable underwater housing options available for the Sony A7 IV, which makes it an excellent choice for most underwater photographers.

The incredible dynamic range of this camera is apparent in this photo of a silvertip shark. f/22, 1/125, ISO 100

The A7 IV is a full-frame mirrorless camera with a 33-megapixel CMOS sensor at its core. It can record 4K/60p video and, combined with Sony's industry-leading autofocus system, most people will find it is more than capable of shooting both stills and video footage. When you consider its price point and what you get for your money, the Sony A7 IV is a strong contender in the underwater camera market.

U.S. MSRP: $2498

Availability: Available at Bluewater Photo

Sony A7 IV Specifications

Sensor: 33MP full-frame CMOS
4k/60p recording in APS-C crop mode only - all other recording formats can be done using the full sensor
Burst Shooting: 10 FPS
Buffer: 828 RAW
Internal Video Recording: 4K/60P, 10-bit 4:2:2
ISO Range: 100-51,200 dual gain ISO. Second base ISO at 3200
Picture Profiles: S-Cinetone, Cine, S-Log2, S-Log3, and HLG log
Storage: One SD UHS-II card slot and one CFexpress Type A card slot
Low light AF: Down to EV -4
Battery Life: 580 shots
IBIS: 5 axis in-body image stabilization
Autofocus: AF tracking with animal eye AF
Autofocus Points: 759 phase-detect
Size: 131.3 mm, 96.4 mm, 79.8 mm
Weight: 658 g (1lb 7.3 oz)
Electronic Viewfinder: 3.7 million dot EVF
Flash Sync Speed: 1/250 and 1/320 in APS-C mode

A Mid-Range Camera Comparison (Canon R6 vs Nikon Z6 II vs Sony A7 IV)

The Sony A7 IV is competing for the same market segment as the Canon EOS R6 and the Nikon Z6 II, so naturally, people will be comparing these three cameras. We know all three well, so let's break down each's features, what we like and what can be improved upon with each.

Photography

The Sony A7 IV has a 33-megapixel sensor, the Canon EOS R6 has a 20-megapixel sensor, and the Nikon Z6 II has a 24.5-megapixel sensor. The winner is clearly the Sony A7 IV based on megapixel count. This is especially important when it comes to macro photography and extracting as much detail as possible from your subjects. However, at $2000 for the body, the Nikon Z6 II is the most affordable camera out of the three, which might sway you if the extra 5.5 megapixels the Sony has isn't worth the extra cost to you.

The autofocus system on the Nikon Z6 II isn't as good as Canon's or Sony's AF systems in the A7 IV and R6. The AF systems in both the Sony A7 IV and Canon EOS R6 perform similarly and are very fast and accurate. In low light conditions, the best AF system is found in the Canon EOS R6. To get around AF limitations, you can use a focus light.

The Sony A7 IV is the overall winner when it comes to photography.

Videography

The winner for video isn't as clear cut as it is for photography out of these three cameras. The Sony A7 IV has more picture profile and codec options for filming, which makes it the top choice if you're going to be editing and processing your footage a lot.

4k/60p is an excellent resolution for recording videos underwater. It allows you to capture stunning details and slow your footage down to give it a cinematic feel. All three of these cameras can shoot 4k/60p video. However, both the Sony A7 IV and the Nikon Z6 II can only record in 4k/60p in APS-C mode, which gives them a 1.5x crop. The Canon EOS R5 also has a crop when shooting 4k/60p, but it's much smaller at only 1.05x.

The Sony A7 IV just edges it for video, especially if you will be editing your videos, but the Canon EOS R6 has slightly better image quality straight out of the camera, which might appeal to people who don't edit their footage.

If you're looking for a great deal, the Nikon Z6 II is an option but apart from price, it falls behind the Sony and Canon in all the other areas we've covered.

Sony A7 IV Improvements from the Sony A7 III

It seems companies release new, updated versions of existing products with a few minor changes every year just because they can. That's not the case with the Sony A7 IV. The A7 IV is such a big upgrade from the A7 III that you can't really call it an upgrade. It's more like a totally new type of camera. Everything is better with the A7 IV.

The extra few hundred dollars it costs to get the Sony A7 IV over the A7 III is well worth it, considering it packs an improved autofocus system, more accurate color reproduction, a clearer menu system, better white balance and enhanced video capabilities. There's not much that isn't better about the A7 IV over the A7 III.

Consider the Sony A7C instead of the A7 III if you're looking for better value camera for underwater photography - it's smaller.

A manta ray photographed with the Canon 8-15mm fisheye lens, Sigma MC 11 adapter, and Sony A7 IV f/10, 1/125, ISO 200

Top Features

Build quality, ergonomics and battery life

Despite being a mid-tier option, the Sony A7 IV is a premium feeling camera. The economics are up there with Sony's flagship models, and there's an argument to be had that they're even better! The A7 IV is comfortable to hold and use, especially for underwater photography. One of the biggest upgrades is the functionality of the mode switch. It now allows you to switch between controlling the photo or video at the flick of, well, a switch! This means that if you are in, let's say, manual mode when shooting stills, all you have to do to get into the video settings is flick the switch to video mode. This will keep you in manual mode but for video, not photo. Before, you would have had to spin the mode dial all the way around until you got to the video settings, a much more time-consuming process.

Silvertip Shark photographed with the Sony A7 IV and Canon 8-15mm fisheye lens in an Ikelite housing with dual Ikelite DS 230 strobes. f/22, 1/125, ISO 100

As with all Sony cameras, the A7 IV has many customizable buttons, but the biggest improvement in its ease of use is the new menu system. Sony originally put its new menu system in the A7S III, and we're glad to see it in the A7 IV. The layout is much better, and the different settings are laid out more logically than before. This is also why you should avoid the older A7 III, as it had the old menu system.

The battery life is nothing short of amazing. After four dives, the battery still had 30% charge left, so you won't really ever have to worry about bringing a spare battery with you for a full day of diving. The Sony A7 IV is rated to 580 shots, which it can comfortably achieve.

Image Quality

For a mid-tier camera, you can't complain about having 33 megapixels at your disposal. It also gives photographers more flexibility in their compositions as you can crop in a lot more without losing too many details in post-production.

A spiny lobster photographed with the Sony A7 IV, Ikelite Sony A7 IV underwater housing, Canon 8-15mm fisheye lens, and Ikelite DS 230 strobes. f/10, 1/125, ISO 400

Overall, the image quality that the Sony A7 IV produces is excellent. The camera can cope well in high dynamic range situations, and you're able to recover a lot of detail from the shadows and rein in the highlights. Even though the A7 IV packs a 33-megapixel sensor, there is surprisingly little noise in images at high ISOs, something which is enhanced further with the "dual gain" ISO feature. Compared to a lot of other cameras on the market, the Sony A7 IV produces excellent files for editing. You can extract lots of details and manipulate colors without making them look unnatural.

Banding

One of the more significant drawbacks of the Sony A7 IV is an issue with banding. During tests, we noticed that there was an issue with banding when shooting into blue water without solid background and trying to recover the shadows. The issue could only be replicated in certain circumstances and alone isn't a reason not to buy the camera, but it's worth mentioning as it might be an issue for wide-angle photographers who often shoot in open water.

"Dual Gain" ISO

The Sony A7 IV achieves something similar to dual gain ISO algorithmically, which means it has two base ISOs: 100 and 3200, much like the high-end Sony A1 and A7S III. Overall, the high ISO performance of this camera is excellent, but having a second base ISO at 3200 means you're better off shooting at ISO 3200 than just below it. Images have hardly any noise in them.

Whitetip Reefsharks photographed with the Sony A7 IV, Ikelite Sony A7 IV underwater housing, Canon 8-15mm fisheye lens, and Ikelite DS 230 strobes. f/10, 1/125, ISO 400

Autofocus

Sony has done it again. The AF system in the A7 IV is incredible and outperforms most cameras from other manufacturers. In AF continuous mode, it doesn't skip a beat and can lock on to your subject's eye with perfect precision. The only aspect of its AF system that slightly lags behind the Canon EOS R6 is the animal eye tracking. The Canon R6 is able to lock on to fish eyes somewhat reliable. The Sony A7 IV is not currently reliable in this respect. In deep water, you may find it hunting for its subject occasionally, but it's nothing to worry about and can be easily fixed with the addition of a focus light.

Whitetip Reefsharks photographed with the Sony A7 IV, Ikelite Sony A7 IV underwater housing, Canon 8-15mm fisheye lens, and a single Ikelite DS 230 strobe. f/10, 1/125, ISO 400

Video Features

The video capability of the Sony A7 IV is one of the reasons why it makes such a great underwater camera. You can easily switch between photo and video modes to ensure you capture every part of your underwater adventure in whichever format you like.

It can shoot in 4k/60p, which is an ideal resolution for capturing underwater video. However, 4k/60p mode is only available with a 1.5x crop, so footage isn't quite at the level it would be if you could use the full width of the sensor, and the effective focal length of your lenses is also affected by the crop. You can shoot in 1080/60p without the crop, but having the extra resolution at 4k/60p makes for better underwater video footage, even if that means dealing with a 1.5x crop.

In some ways, the 1.5x crop can be a good thing, such as not having to get as close to your subjects as you would have to otherwise. But it also means that your video lights won't be as effective since you'll be further away from what you're trying to shoot.

When it comes to video profiles, the Sony A7 IV comes packed with plenty to choose from, including HLG, S-Log2, S-Log3 and S-Cinetone. Video editors will be happy with the color science of the files and the results once they've been processed. You can recover lots of detail from the shadows and highlights, especially when using the S-Log3 profile.

Overall there is little to separate the 4k footage from the Sony A7 IV from Sony's high-end cameras such as the A7S III or A1. Apart from the 1.5x crop, most people won't be able to tell the difference, which is impressive considering the price point of the A7 IV. The A7S III and A1 do, however, perform much better in low light. So if you are a serious videographer, you would still want to consider these cameras.

Best Wide-Angle Lenses for the Sony A7 IV

For both photo and video, the Sony 16-35mm F4 lens with an 8-inch dome or larger is an excellent choice. There are also some great wet wide-angle lenses available such as the Nauticam wet wide-angle lens or the Kraken KRL-01 wet wide-angle lens that can be used with the Sony 28mm prime lens. The Sony 28mm prime lens also works well with a fisheye conversion lens to capture even wider shots of large reefscapes.

A humpback whale and calf photographed with the Sony A7 IV, Canon 8-15mm fisheye lens, Sigma MC 11 adapter, in an Ikelite A7 IV housing with a single Ikelite DS 230 strobe. f/13, 1/125, ISO 320

If you're looking for the most versatile wide-angle Sony set up for underwater shooting, the Sony FE 28-60mm F4-F5.6 lens behind a flat port with zoom capability paired with the Nauticam WWL-1B Wide-Angle Wet lens is the way to go. The downside is that it's currently only compatible with Nauticam and Marelux housings. Check out the Underwater Photography Guide's article about the Sony FE 28-60mm F4-F5.6 lens for more information.

Best Mid-Range Lenses for the Sony A7 IV

The Sony 28-70mm F3.5-F5.6, the Sony 24-70mm F4 and the Sony 35mm F2.8 portrait lens are three good mid-range options.

Best Macro Lenses for the Sony A7 IV

There are two native Sony lenses that we think are great macro options: the Sony 90mm and 50mm macro. The 90mm has a faster autofocus motor, but if you need to get a little more in your composition, the 50mm macro does an ok job.

Recently, we reviewed the Sigma 105mm f/2.8 DN DG Art macro lens. It's an excellent and more affordable option to the Sony 90mm with better image quality. However, it is not a great choice for video due to focus breathing.

We already mentioned the Sony FE 28-60mm F4-F5.6 lens and how it makes a great wide-angle option when used with a wide-angle wet lens, but combine it with the Nauticam Compact Macro Converter CMC-2, and it becomes a very versatile and highly capable macro set up too.

Canon Lenses for the Sony A7 IV

Canon lenses can be attached to the Sony A7 IV with the Metabones, Sigma MC-11, or Photodiox adapters, but auto-focus is generally better with Sony lenses. Lenses like the Canon 8-15mm, 16-35mm, 17-40mm, and 100mm can work well. I found that the Canon 8-15mm fisheye lens worked better with the Sigma MC-11 adapter than with the metabones adapter.

Sony A7 IV Underwater Housings

Currently, there are underwater housing options available for the Sony A7 IV from Marelux, Nauticam, and Ikelite. We anticipate more from Sea & Sea and Isotta coming soon.

Click Here for Our Guide to Sony A7 IV Underwater Housings

Conclusion

The Sony A7 IV is a massive step up from the A7 III, so much so that it's competing with Sony's flagship model, the A1, and the video-focused A7S III. The new menu system and the file's color rendition make the A7 IV a very strong contender in the mid-range full-frame mirrorless camera market.

If you're looking for a reliable workhorse that can shoot photos and videos equally well, then the Sony A7 IV could well be the camera for you.

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