Sony Alpha A9 vs Sony Alpha A7s II – Should You Upgrade?

Sony’s latest Alpha A9 appears as a serious proposition for sports and action photographers, but how does it compare on the spec sheet with the Alpha A7s II? Let’s find out.

Design and Ergonomics

In terms of design the two don’t differ all that much, but the age gap between them, together with the fact that they’re each aimed at a slightly different user, mean they aren’t quite identical.

The Alpha A9 features an additional control dial on the top plate that allows the drive mode to be changed rapidly, and underneath this Sony has provided a collar for changing the focusing mode. This is complemented by a joystick on the rear that allows the AF point to be quickly shifted, together with a customisable AF-ON button in place of the Alpha A7s II’s AF/MF and AEL controls.


Sony Alpha A7s II


Sony Alpha A9

Other smaller changes include a slightly restyled grip on the Alpha A9 and a different design for the rear menu pad dial too, as well as a refreshed menu system on the inside. The Alpha A9 also offers the relatively new Slow & Quick video mode and an additional memory option on its mode dial, in place of the Scene and Panorama options found on the Alpha A7s II’s.

The Alpha A9 also adds flash sync and LAN ports to the same USB, HDMI, mic and headphone ports that feature on the Alpha A7s II, together with an additional card slot. It’s also around 50g heavier too, but only a few millimetres deeper.


Sony Alpha A7s II


Sony Alpha A9

Image Quality

The Alpha A7s II is designed with sensitivity in mind. It sports a 12.2MP full-frame Exmor CMOS sensor, with a sensitivity range that can be expanded to ISO 50 and 409,600 equivalents.

The Alpha A9, meanwhile, adopts a newer sensor with a back-illuminated, stacked design, with its own memory to help the camera crunch through images at up to 20fps. Its 24.2MP effective pixel count is significantly higher by comparison, and that fact that it can have its ISO range expanded to ISO 50- and ISO 204,800-equivalent settings means it can soldier in all manner of shooting conditions.


Sony Alpha A7s II


Sony Alpha A9

Both bodies offer built-in image stabilisation over five axes, although Sony claims the system on the Alpha A9 is slightly more effective, with a maximum five-stop advantage versus the Alpha A7S II’s 4.5 stops.

Special Features

Targeted towards the action photographer, the Alpha A9 has its focusing system and burst rate as its two major selling points. It can fire at up to 20fps with AF and auto-exposure maintained throughout, with AF/AE calculations performed 60 times per second. This is partnered with a Fast Hybrid AF system that boasts 693 phase-detect AF points across 93% of the frame, together with 25 contrast-detect AF points.

In contrast, with its 169-point contrast-detect AF system and maximum burst rate of 5fps, the Alpha A7S II appears a little behind. As we may expect from a camera designed for low-light shooting, however, its working range is a little more impressive, rated down to -4EV against the Alpha A9’s -3EV.

While the Alpha A7s II’s viewfinder is constructed with a 2.4million-dot OLED panel, the Alpha A9 has a more impressive 3.7million-dot panel, with a maximum 120fps refresh rate and a fluorine coating on the outer optic to help protect it from dirt and grease. Sony also claims there is no blackout at all when shooting at up to 20fps on the Alpha A9, something it has not claimed for any previous model.


Sony Alpha A7s II


Sony Alpha A9

The LCD screens on the two models appear similar to the eye, but changes have been made here too. Not only does the Alpha A9’s display sport a marginally higher resolution – 1.44million dots vs the Alpha A7s II’s 1.23million dots – but it also has the advantage of touch operation. The way each moves, however is exactly the same, with downwards tilting over 107 degrees and upwards tilting over 41 degrees.

While the Alpha A7s II is powered by an NP-FW50 battery, one that allows for around 310 frames with the viewfinder and approximately 370 frames with the LCD, the Alpha A9’s NP-FZ1000 cell boosts these figures to around 480 frames with the viewfinder and approximately 650 with the LCD.

Video Quality

When Sony launched the Alpha A7s II, the big news was that it could record 4K internally, something its A7s predecessor couldn’t do. This has, of course, now been matched by a number of other models, but the camera still holds up pretty well where video specs are concerned.

Both models can capture 4K UHD video (3840×2160 pixels), will full pixel readout and no pixel binning, and both are supported by a range of features such as zebra, clean HDMI out and the option to append time code to footage.


Sony Alpha A7s II


Sony Alpha A9

The A9 oversamples the scene to capture 6K worth of footage before this is condensed down to 4K for the benefit of image quality, and it also offers the Super 35mm crop option on top of this. While both cameras also allow for footage to be recorded at up to 120fps in Full HD for the purpose of creating slow-motion footage, only the Alpha A9 offers the Slow & Quick mode that allows finer control over the frame rate right down to 1fps.

Sony also claims that the Alpha A9’s redesigned sensor allows for rolling shutter to be reduced, although those looking to take video more seriously might be irked by the absence of the same S-Log profiles that appear on the Alpha A7s II.


In many respects the Alpha A9 is the superior camera out of the two here. Its sensor boasts a more modern design while its viewfinder and LCD are higher in resolution, with the touch functionality presenting another advantage over the older model.

Furthermore, the Alpha A9’s AF system appears far more capable, and with the changes Sony has made to the physical controls, focus and drive mode options can be accessed more conveniently too. And that’s on top of a wealth of smaller refinements across many aspects of its spec sheet.

Yet, it’s considerably more expensive than the Alpha A7S II right now, and for many people the more advanced feature set may be overkill. The Alpha A7s II still a relatively recent camera, after all, and there are a number of reasons why it’s the finder model if video is your thing. If you’re happy with it ‘only’ having a 12MP sensor then you may well find it to be the better fit of the two.