Sony A7II v Sony A7III – Should You Upgrade?

How does the update to the Sony A7 range compare to its predecessor?
How does the update to the Sony A7 range compare to its predecessor?

For many photographers looking to take up shooting with a full frame Compact System Camera, the Sony A7 series is often the entry point as it offers a range of impressive and versatile features. It’s also the most competitively priced, being more affordable than both the high resolution A7R series and video-focused A7S offering. When all three cameras were upgraded to the Mark II generation around 3 years ago, the A7ii lagged behind the pace of its siblings on certain specs – particularly the autofocus offering – and this was reflected in the pricing. Well that’s all about to change with the arrival of the Sony A7iii, which inherits a number of features from Sony’s flagship mirrorless camera – the A9, raising the benchmark of what’s to be expected from an entry-level full frame CSC. To see what progress has been made, let’s compare the A7ii with the A7iii to find out if it’s worth upgrading.


The A7iii features a newly designed 35mm Exmor R full frame sensor with a 24.2MP resolution. Although this is a fractionally lower pixel count than the A7ii’s 24.3MP, the new sensor is back-illuminated – making it better at gathering light – and has a front-end LSI chip which increases the read out speed for a faster performance. Some may view the resolution reduction as a negative, but it makes no discernible difference to detail captured and the new design of the sensor makes for an overall better performance in areas including Dynamic Range, ISO, shooting speed and autofocus. The A7iii also comes with an updated BIONZ X processor which helps get the best performance from the new sensor.

The Sony A7iii (right) has a newly designed back-illuminated 24.2MP sensor

Both sensors are also aided by a 5-axis image stabilisation system to help reduce camera shake. This has been slightly enhanced in the A7iii and it now allows for 5-stops of correction, compared to 4.5-stops in the A7ii.

Both cameras feature a 5-axis image stabilisation system

The faster performance of this new sensor and processor pairing is evidenced by the top shooting speed of the two cameras. The A7ii was capped to a maximum frame rate of 5fps and limited to a burst of 50 JPEGs or 20 RAW files. The A7iii massively outpaces its predecessor with a top shooting speed of 10fps – that’s with Continuous Autofocus and Automatic Exposure – and can capture 177 continuous JPEGs or 89 RAWs. This makes the A7iii much more appealing to professionals who need that faster frame rate and bigger buffer depth. And what’s more, Sony’s latest A7 offering will also shoot up to 10fps in Silent Shutter mode; ideal for either wedding photographers or those photographing easily spooked wildlife.

The back-illuminated sensor of the A7iii helps deliver an enhanced sensitivity performance with a native ISO range of 50-51,200, a stop greater than the A7ii’s 50-25,600. The A7iii also goes a stop further when it comes to the Dynamic Range at lower ISOs, and can capture 15-stops of detail in a single exposure.

Where the A7iii really shines is with the AF system. Like Sony’s flagship A9, it offers an incredible 693 phase detect points covering 93% of the frame, and 425 contrast detect points located towards the sensor to help achieve focus even faster. Compare this to the A7ii’s 117 phase detect points and 25 contrast detect points and you can see the chasm between these two generations. Sony also claim that the A7iii is twice as fast at focusing in low light with the sensitivity increased from -1EV to -3EV. The new AF system also features Sony’s 4D Focus, which tracks a moving subject while predicting its next movements based on its speed and location in the frame, making it doubly quick at tracking moving subjects compared to the A7ii.

The A7iii uses 693 phase detect AF points which cover 93% of the frame area

Arguably the biggest drawback of shooting with a CSC has traditionally been the battery performance, since these cameras are very power hungry. The A7ii battery is good for around 350 shots, meaning photographers would need a bundle of spares to see them through the day. The battery of the A7iii has been significantly improved and extends the shooting time to 710 frames, making it much more appealing to professionals.

One of the key reasons why CSCs demand so much battery power is the EVF. Both the A7ii and A7iii feature the same 0.5in OLED viewfinder with 2.3M dots, however Sony has tweaked the optical design to produce a higher magnification of 0.78x compared to the 0.71x magnification of the A7ii. The cameras also house a 3.0in LCD, but surprisingly the A7iii offers a lower screen resolution of 921k-dot versus the 1228k-dot of the A7ii. However, despite the reduction in screen pixels the A7iii LCD is touch sensitive, allowing you to set the AF point with the tap of a finger for faster handling and to zoom in to check image focus. The touch functionality is limited though, and it can’t be used for scrolling through images or making menu selections as you might expect.

Both feature a tiltscreen, but the A7ii offers a better resolution while the A7iii has touch functionality

Although this series isn’t aimed directly at videographers – that’s the domain of the A7S line up – the movie performance has been updated in the A7iii. While both come with ports for both microphone and headphone inputs, the A7ii can capture Full HD at 60fps. This frame rate has been doubled on the A7iii to 120fps, allowing for smooth slow motion and will also shoot 4K video at 25fps.

Build & Handling

There’s also been a few tweaks to the body design between these two generations, and the improvements have been inherited from the top end A9 and A7Riii. The video record button has been shifted towards the EVF for better access, and there’s a new mini joystick on the rear to aid AF selection when using the viewfinder. It falls conveniently under the thumb making for quicker operation than the clunkier method required on the A7ii.

The A7iii also comes with two SD card slots, one offering UHS-II compatibility and the other slot UHS-I. The A7ii just features on UHS-I SD card slot. Having two SD cards means you can divide your RAWs and JPEGs, use one for stills and the other for video, or simply as an overflow. Both cameras feature NFC and WiFi connectivity, but the A7iii now also comes with BlueTooth which consumes less power.

For peace of mind both cameras are constructed from durable magnesium alloy and they are dust and splash proof. The A7iii has a slightly deeper profile than the A7ii, and also tips the scales further at 650g compared to 556g (body only).


Sony’s update to the A7 series is fairly comprehensive, with significant boosts and upgrades in almost every area of the camera. The A7iii massively outperforms its predecessor on the AF system and shooting speed, and also brings welcome enhancements to the ISO, video capability, image stabilisation and plenty of handling improvements too. One area that may sway you in favour of the A7ii is the price. Currently it has an RRP of £1350, though better deals can be found, making it a truly appealing camera for those on a budget wanting a full frame mirrorless. If you want access to the latest features of the A7iii, you’ll need to stump up £1999. All things considered the A7iii is worthy of the higher price tag, so if you’re tempted to upgrade, you’re unlikely to be disappointed.

Key specifications

Sony A7ii Sony A7iii
Price $ 1,029.00 $ 1,829.00
Sensor Full-frame (35.8 x 23.9mm) Full-frame (35.9 x 24mm)
Resolution 24.3MP 24.2MP
Processor Bionz X Bionz X
ISO range 50-25,600 50-51,200
Shooting speed 5fps 10fps
Continuous shooting 50 JPEG/20RAW 177JPEG/89RAW
AF points 117 phase-detect 693 phase-detect
Image stabilisation Yes; 4.5-stops Yes, 5-stops
LCD monitor 3.0in 1228k-dot 3.0in 921k-dot touchscreen
Video resolution Full HD (1920×1080) 4K (3840 x 2160)
Battery life 350 shots 710 shots
Storage SD/SDHC/SDXC (UHS-I) Dual card slots, Slot 1: SD(UHS-I/II compliant), Slot 2: Memory Stick Duo/SD(UHS-I)
Weight 556g 650g
Dimensions 126.9 x 95.7 x 59.7mm 126.9 x 95.6 x 73.7mm
Date announced 20th Nov 2014 27th February 2018