Sony has been the fist brand to produce a full frame mirrorless camera in 2013 with the Alpha 7. Ten years later Sony is a market leader in Digital Cameras and their division Sony Semiconductors is the market leader in sensor technology for a variety of applications, mobile phones, security and of course digital cameras.

It is not all rosy though, Sony ergonomics and menu system have been historically not intuitive with many people criticising or simply despising it.

In July 2020 Sony releases the A7S III a low megapixel camera completely focussed on video functionality with a strong performance in low light.

The A7S III offered a completely redesigned menu system and this was very well received by the public.

The ergononics were greatly improved and many video users started to convert to Sony, there were and are still some quirks but the useability had greatly improved from past model.

Since then the Alpha 1 announced in January 2021, the A7 IV and now the A7RV all have benefited from the new menu system and improved ergonomics.

An additional important detail is that Sony cameras are small and portable with weights between 650 and 740 grams this means underwater housing are also compact.

The Sony E-Mount system is the most popular full frame mirrorless format and is supported by many 3rd party lens manufacturers: Sigma, Tamron, Samyang and others.

It is also the most popular and more affordable full frame format for underwater photography with many housing options.

But what is more exciting is that the Sony E-Mount has extensive support of water contact optics from Nauticam and there is even an adapter to use Nikkor water contact lenses.

And finally the auto focus system of Sony full frame camera is market leading and Since the A1 sports subject detection with improvements trickling into the entire range.

So many DSRL users have been sitting on the fence waiting and keeping hold of their rigs but now in 2023 there really is a lot of choice and the Sony system supported by Nauticam housing and port system can offer options to all type of underwater photography shooters.

I have done myself a lot of research and tried many of those cameras before deciding what to get and I want to share some of my thinking with you.

The 2023 Line Up

As of today I would consider only 3 Sony full frame camera for underwater photography and those are:

• A1
• A7R5
• A7 IV

This is a small comparison table with some key data points:

Solution	Camera RP	Housing Rp	Combined Price	Megapixels	Readout	Flash Speed	EVF	LCD
ILCE-1	5879	3497	9376	50.1	200	1/400	3.145	0.480
ILCE-7R5	3999	3324	7323	61	15	1/250	3.145	0.698
ILCE-7M4	2399	3180	5579	33	15	1/250	1.228	0.345

I will discuss the cameras from top to bottom. You can see that the price difference between the housings is not large but the price of the cameras are varying significantly.

Sony ILCE-1 aka A1

This camera sits on top of the current range of Sony full frame cameras and rightly so. The heart of the camera is a 50.1 megapixels stacked back illuminated sensor capable of a readout speed of 200 frames per second.

This means that the A1 is able to offer a black-out free shooting experience when the electronic shutter is used.

The other interesting characteristic of this camera is a flash sync speed of 1/400 s using mechanical shutter and the ability to trigger flash with electronic shutter up to 1/200 s.

The camera also offers a super high resolution viewfinder capable of 2048 × 1536 (QXGA) pixels although the best image quality is only available when the EVF is refreshed at 60 frames per second.

The A1 has many dials and controls including dedicated ones for exposure compensation and drive mode and generally feels compact and well built but perhaps not as robust as other premium models from Nikor or Canon.

It also offers 8k video up to 30 fps and 4k video up to 120 fps with a small crop. In general terms the A1 is still two years from its release the fastest camera on the market with a burst speed of 30 fps with autofocus.

Talking of autofocus this is simply the best AF on the market with subject eye detection and a very competent tracking mode for general purpose use.

I have the A1 myself if money is no object I would definitely recommend it if you are interested in a camera that is very fast to operate and has amazing video.

Nauticam offers an housing with all features available except touch screen.

Looking at the back of the housing you can see that even the multi function button is controlled by the housing.

For a review of the housing go to Underwater Photography Magazine and select issue 120.

Due to the compact size of the camera the housing itself is very compact for a full frame camera. A plus point is that the Nauticam housing can also be used for the A7S III with an adapter.

Sony ILCE-7R5 aka A7R5

This camera has recently been released and while the sensor is identical to the previous A7R4 the R5 offers the new improved menu system and a redesigned autofocus engine with subject detection.

The A7R5 has 61 megapixels and possibly the best image quality on the market for a full frame mirrorless camera.

The A7R5 has a single main dial with a subdial for movie and other modes. No dials exist for the drive.

The camera shares the same amazing EVF of the A1 but it has a fully articulated high resolution LCD.

The sync speed is a respectable 1/250 however the A7R5 has a very slow read out of 15 frames per second. This means video has a lot of rolling shutter and the burst rate is low as the camera reads slow and has many megapixels.

Nauticam has recently released the housing for this camera.

The housing is slightly simpler than the A1 due to the reduced number of controls and is very similar in size.

For a review of the housing go to Underwater Photography Magazine and select issue 130.

I believe the A7R5 will be a very popular choice for the underwater photographers and it is the perfect choice if IQ is your priority and in addition to underwater you also like landscape, architecture photography topside and video is not really your priority.

Sony ILCE-7M4 aka A7 IV

The A7 IV was released in fall 2021 and has marked a significant improvement over the very popular A7 III with a jump from 24 to 33 megapixels, improved EVF and autofocus and 4k video up to 60 fps with APSC crop.

The camera weakest point is the read LCD that has a very low resolution but otherwise this is a respectable camera with a price that has increased compared to previous models.

The camera body is very similar to the A7R5 and in general Sony cameras are fairly similar when it comes to a new release.

The housing is again very similar to the A7R5 due to the similar controls.

Although the EVF is ‘only’ 1280×960 this is perfectly adequate to check critical focus. Same cannot be said for the LCD and if you plan on getting this camera an underwater viewfinder is a must.

This camera like the A7R5 has a slow read out rate of 15 fps so it is not the best choice for fast moving subjects and burst but the AF is very functional so it will work well for your occasional kid running.

The A7 IV is a great choice is you like shooting in a variety of situation and especially in low light and you are not fussed by high megapixel count. In addition video quality is great and the APSC mode is very functional. It is a camera you can expand with accessories if you like.

Which camera is for me?

When it comes to choice this is mostly driven by your budget. While there are certainly differences in performance and functionality across the 3 models discussed all of them are perfectly capable of taking magnificient underwater images. Comparing sensor performance we can see we are splitting hair here. (The comparison is with the A7R4 that has the same sensor so it will be indentical)

I suppose it is somewhat suprising that the scores are so close but we need to take into account that those are normalised back to 8 megapixels.

In general terms I believe the A7R5 will be the most sought after model for underwater photography because of the high megapixel count, the high quality EVF and LCD and the functionality of the autofocus.

However if you can not or do not want to afford it the A7 IV is a very respectable choice. The LCD I believe is the key limitation of an otherwise very competent camera and frankly 33 megapixels are plenty.

The A1 will appeal to hybrid users that want the best photos and video and are most likely doing other form of wildlife shooting where speed matters.

Whatever you choose you cannot go wrong with the latest Sony models.

In the upcoming articles choosing the right ports for keeping your Sony full frame underwater system still portable.