SONY A7S III
What happens when you design a hybrid mirrorless camera for the discerning video-maker? You get a hybrid mirrorless camera for the discerning photographer too.
It’s the Alpha series mirrorless camera that Sony primarily targets at professional video-makers, but in making the A7S III so good in this application, it’s also made it very attractive as a purist’s stills camera. Here’s why.
There are many good reasons why Sony is racing to the top of the interchangeable lens camera market with its full-frame mirrorless system. A range of close to 40 FE-mount lenses is a good start, but it’s also nailed it with its current generation of Alpha series camera bodies. You want high res? The A7R IV is currently unbeatable here.
You want high speed? The A9 II is the camera for the job. You want both high res and high speed? The new Alpha 1 ticks both boxes. You want something more compact? OK, it’s the A7C then.
Video is your thing? The A7S III is optimised for pro-level shooting in either 4K or Full HD.
Sony has been realistically sober with the A7S III’s video spec, deliberately avoiding the hoopla of 8K that's still a long way off being usable anywhere other than in-camera. It will certainly give you ultra-high quality masters – albeit with massive file sizes – and some improvements in colour and detailing will remain after downscaling to 4K thanks to the oversampling of each pixel. But in terms of post-production, display and delivery, the professional video world is still largely dealing with the upgrade to 4K. Conventional overthe-air broadcasting in 4K is still a long way off and, while there are streaming options you’ll need the right internet connection to handle the increased bandwidth. 8K? Forget it. So Sony has concentrated on making the A7S III as accomplished at recording 4K video as is possible via a big selection of frame rates, codecs, compression and colour sampling… starting with UHD recording internally at 100/120p with 10-bit 4:2:2 colour and audio, while still retaining full autofocusing capabilities (see the Making Movies panel for the full story).
What’s interesting here, though, is that in the process of designing a hybrid mirrorless camera for the video purist, Sony has also ended up with a camera for the photographic purist too. Yes, forget 61MP, 50MP or even 24MP. How about 12MP? We’re becoming so accustomed to the ultra-high pixel counts that we’ve largely forgotten that, again in real world terms, 12 megapixels resolution is quite sufficient for a wide variety of applications. There are other, arguably more important, aspects of image quality to consider here, and less can indeed be more when it comes to pixel counts. The total pixel count is 12.9 million which, on a full-frame sensor, gives a pixel size of 8.36 microns… and this is essentially medium format camera territory. Bigger pixels mean a higher signal-to-noise ratio which, in turn, means a wider dynamic range – 14 stops for stills in this instance – and increased sensitivity. The native range is equivalent to ISO 80 to 204,800, expandable to ISO 40 and 409,600.
So the A7S III is a pretty impressive performer in low-light situations.
Of course, there’s the question of why you’d spend all that money – around $1,000 more than the 61MP
A7R IV and twice the price of the 24MP A7 III – if you weren’t going to put this camera’s excellent video capabilities to good use. But the sensor that makes the A7S III work so well as a video camera is equally beneficial for stills too.
And to this you can add 10-bit
HEIF capture (as an alternative to 8-bit JPEGs), 10fps continuous shooting with full AF/AE adjustment, 759-point autofocusing with low-light sensitivity
down to EV -6.0 (ISO 100 and f/2.0), a big EVF with a resolution of 9.44 million dots and a magnification of 0.9x, a fully-articulated rear screen (actually a first on a Sony A7 series body) and the option of using the super-fast CFexpress Type A memory cards while retaining compatibility with the popular SD format. There’s plenty more, of course, but how’s that for the basis of a very appealing stills camera?
Pick A Card
The Sony A7S III is the first camera to use the more compact Type A CFexpress card, which is quite a bit smaller than Type B (the one commonly available) and even a bit smaller than SD, but is capable of a read speed of up to 800 MB/second and a write speed of up to 700 MB/second… so they’re over twice as fast as the speediest UHS-II SD card. Consequently, Sony says burst lengths of over 1,000 frames are possible with RAW capture (thanks also to a bigger buffer memory), and this obviously also allows for 4K at 120fps for up to 20 minutes. The size difference with SD requires a dual-format arrangement for the card slot – what Sony calls a “multi slot” – and there are two of these so you can mix and match cards as well as set up either backup or relay recording, or assign a file type to a specific card. While the multi slot will actually accept two cards at the same time, they can’t be used together. Needless to note, however, the SD card slots are compatible with UHS-II speed devices. Sony is currently offering either 80GB or 160GB capacity versions that are, at this point, all that’s available. You’re currently looking at around $300 for the 80GB card and $680 (ouch) for the 160GB device, but if you’re mostly shooting stills a UHS-II speed SD card will easily do the job.
The maximum image size is 4240x2832 pixels, and JPEGs can be recorded at two smaller sizes with a choice of three compression settings and four aspect ratios – 3:2, 4:3, 16:9 and 1:1. The same selection of capture settings is available for HEIF capture, while RAW files can be captured either uncompressed or lossy compressed. Sony joins Canon in offering the 10-bit HEIF alternative to 8-bit JPEGs, and it’s essentially the still derivative of the more efficient HEVC H.265 video codec. The initials stand for High Efficiency Image Format and it delivers both a wider dynamic range and a wider colour gamut without increasing the file size. In fact, twice as much information can be saved in an HEIF file as in a JPEG of the same size. It creates much more natural HDR stills than the artificial-looking simulation processing of JPEGs. The
A7S III offers the option of recording HEIFs with either 10-bit 4:2:2 colour sampling or 10-bit 4:2:0. In-camera HEIFto-JPEG conversion is available, and even these JPEGs will still have a wider dynamic range. RAW+HEIF capture is also available on board.
The sensor is mated with a new and faster Bionz XR processor which, Sony’s says, is eight times more powerful than the previous generation Bionz X, three times zippier than the previous X version and also reduces rolling shutter distortion by a factor of three over the A7S II. The maximum continuous shooting speed of 10fps is available when using either the mechanical or electronic shutter, and you get realtime live view with the latter at up to 8fps, again with full AF/AE adjustment. In reality, you’re highly unlikely to ever challenge the 1000+ frames burst length that applies to RAWs (either compressed or uncompressed), and maximum-quality JPEGs or HEIFs when using a CFexpress Type A memory card. With a UHS-II speed SDXC card, the burst lengths are reduced, but are still very generous.
In-body image stabilisation is provided via sensor shifting which, in along with lens-based optical image stabilisation, operates over five axes and gives up to 5.5 stops of correction for camera shake. This obviously helps make the most of the camera’s inherent low-light shooting capabilities. Interestingly here though, Sony hasn’t taken the opportunity to use sensor shifting to give a higher resolution image via multi-shot capture with in-camera merging. This would have been a bit of extra icing on the cake for stills shooters, but it perhaps shows where Sony’s main priorities lie with the A7S III.
You also see this with the camera’s set of Creative Look picture presets
Sony has concentrated on making the A7S III as accomplished at recording 4K video as is possible via a big selection of frame rates, codecs, compression and colour sampling.
rather than the Creative Styles that photographers will be more familiar with. The Creative Look presets have been borrowed from Sony’s much-lauded Venice 6K pro cinema camera and have double initials as designations rather than descriptors such as Standard, Portrait or Vivid. You can pretty well work out what stands for what with most of them – ‘ST’ is Standard, ‘PT’ is Portrait, ‘NT’ is natural, ‘VV’ is vivid, ‘VV2’ is also vivid with brighter tones, ‘BW’ is B&W and ‘SE’ is Sepia. However, ‘FL’, ‘IN’ and ‘SH’ – which, incidentally, are all new – may have you scratching your head. ‘FL’ stands for Film Like, and is described as creating a “moody finish”. ‘IN’ represents Instant (camera) and gives “matte textures” by reducing contrast and saturation. ‘SH’ stands for Soft & High Key and is designed to produce an image that has a “bright, transparent, soft, and vivid mood”. Got it?
The Creative Looks have adjustable parameters for contrast, highlights, shadows, fade, saturation, sharpness, sharpness range, and clarity. All are set via numerical value ranges. Alternatively, you can create up to six custom ‘Looks’. Of course, everything can be previewed in the excellent high-res EVF. There are no built-in special effects.
Noise reduction is provided for both long exposures and high ISO settings, plus Sony’s long-standing Dynamic Range Optimiser (DRO) processing is retained, but there is no multi-shot HDR mode because you probably don’t need it given the availability of 10-bit HEIF and HLG (Hybrid Log Gamma) Still Image capture. The DRO options comprise auto correction – based on the contrast range of the scene – or five levels of preset correction. An auto bracketing mode is available for dynamic range expansion processing, as well as for white balance and exposure. In-camera lens corrections are provided for vignetting (i.e. brightness fall-off), chromatic aberrations and distortion. The A7S III has flicker detection and correction for more stable exposure control when using continuous shooting under gas-ignition light sources (i.e. fluoro types) which, for example, are common in indoor sporting venues. These actually switch on and off continuously, but at such a high frequency that it’s largely imperceptible to the human eye, but can make quite a difference to exposures and colour balance. So, the anti-flicker function adjusts the shutter’s timing very fractionally during a continuous sequence to avoid this.
There’s an intervalometer programmable for up to 9,999 shots and includes an adjustment for AF tracking sensitivity. No multiple exposure facility though.
Keep On Tracking
With the new sensor comes a new version of Sony’s Fast Hybrid autofocusing system employing a total of 759 phase-difference detection and 425 contrast-detection points, with 92% frame coverage. Low-light sensitivity extends down to EV -6.0 at ISO
100 and f/2.0. AI-based subject recognition drives the
camera’s Real Time Tracking based on colour, pattern, distance, and face and eye data. Additionally, the Real Time Eye AF can be switched between humans and animals, with the option of auto or manual right/left eye selection with the former. Sony says performance has been improved by 30% and it’s able to keep tracking even if the subject looks away or there’s an interruption caused by another object passing in front. Additionally, tracking sensitivity can be varied over five levels from Locked On to Responsive. There’s also the choice of focus or speed priority (or a balance of both), set independently for the single-shot and continuous modes. Switching between the single-shot and continuous modes can be done manually or left to the camera when it’s set to AF-A. Similar to the A9 II, there’s an Aperture Drive in AF setting that has the option of selecting focus-priority or silent-priority, the former maintaining an open aperture during autofocusing in order not to degrade the viewfinder image. Normally, you wouldn’t notice anything, but with the A7S III’s no-black-out EVF operated at 8fps, the lens continually stopping down would create annoying flickering.
There’s a choice of five area settings, namely Wide, Zone, Centre Fix, Spot and Expand Spot. All five are also available with tracking. In the Spot modes, the focusing zone can be set to one of three sizes – small, medium or large – to fine-tune selectivity. In the Expand modes,
the surrounding points are automatically selected if the subject subsequently moves. Continuous AF is supplemented by a Lock-On function that works with any of the area modes to provide more reliable tracking. A focus point or area can be registered for instant recall, which is useful when shooting the same scene or subject on a regular basis. Additionally, it can be set to switch position automatically when the camera is turned to the vertical position. The AF frame can be switched between white and red to enhance visibility. The A7S III also has the Circulation Of Focus Point function introduced with the A9 II that enables the focus area to be rotated through the upper, lower, left, and right edges of the frame – primarily designed for situations where a subject often moves through the frame. A number of autofocusing functions are available via the rear display’s touchscreen, including the selection or moving of a focusing point/zone, and a ‘Touchpad’ option that allows this to be done when using the EVF (with the choice of absolute or relative positioning on-screen). Additionally, Touch Tracking allows you tap on a subject to start the process.
The manual focus assists comprise a magnified view and a focus peaking
The wide dynamic range translates into huge exposure latitude so, with RAW files, there’s up to four stops of get-outof-jail exposure correction.
display. The latter can be set to red, blue, yellow or white and high, mid or low intensity. The focus magnifier can be set to operate continuously or for timed durations of two or five seconds. Handily, it’s also available with autofocusing to help confirm focus.
The exposure control options are the standard Sony A series fare, and based on 1,200-point on-sensor metering with the choice of multizone, centre-weighted average, fully averaged, highlight-biased or spot measurements. The spot meter’s size can be switched between standard or large, and either locked to the frame’s centre or linked to the active focus point(s). Multi-zone metering can be set to face-priority. Auto exposure control mode overrides comprise an AE lock, exposure compensation of up to +/-5.0 EV (although the dial is only marked to +/-3.0 EV so going further requires a trip to the relevant menu) and auto bracketing over sequences of three, five or nine frames. The standard set of ‘PASM’ exposures modes is supplemented by a fully-automatic mode providing subject/scene analysis and adjust the capture settings accordingly.
The mechanical shutter has a speed range of 30-1/8000 second, with flash sync up to 1/250, and there’s the option of a sensor-based electronic shutter for silent and vibration-free shooting (with the same speed range). There’s also the hybrid electronic front curtain shutter that starts the exposure with the sensor shutter and finishes it with the conventional one. This provides some reduction in vibrations and noise while still allowing the use of electronic flash.
Auto white balance controls offer the choice of three modes – Standard, White-Priority or Ambience-Priority. Alternatively, there are a total of 10 presets – including four for different types of fluoro lighting and one for shooting underwater – with fine-tuning over the blue-to-amber and green-tomagenta colour ranges. Manual colour temperature setting is available over a range of 2,500 to 9,900 Kelvin. Up to three custom white balance settings can be created and, as noted earlier, white balance bracketing is available over a sequence of three frames.
In The Hand
The A7 series cameras have put on a bit of weight since the first generation models, but they’re still among the most compact full-framers on the market. The A7S III’s size and styling are very similar to that of the A7R IV and A7 III, with a generously sized handgrip and a matteblack finish.
The body covers are magnesium alloy with upgraded weather sealing and, as you’d expect for a professionallevel camera, the A7S III feels very solidly built. The control layout centres on a main mode dial with front and rear input wheels, a rear panel navigator wheel (incorporating a four-way keypad) and a joystick control that Sony calls a “multi-selector”. There’s a dedicated dial for setting exposure compensation (which is lockable), and the video start/ stop button has been moved to the top panel, located just behind the shutter release which is much more convenient. The customisation options include four multi-functional ‘C’ buttons, the rear control wheel and its keypad quadrants, and the on-screen Function Menu comprising 12 tiles for direct access to the assigned items. There are dedicated Function Menus for photography and video, while the customisable controls have three setups for photography, video and playback. Additionally, there’s My Dials customisation for the input and control wheels. There's, of course, a customisable My Menu, and up to four banks of camera setups – designated M1 to M4 – can be created, with three of them assigned to the 1, 2 and 3 positions on the main mode dial.
The A7S III introduces a completely new menu design that employs progressive click-right navigation to take you from chapter to page to sub-menu and settings. The chapters use colour-coded tabs, and the same colour is used for the page numbers, making it much easier to see where you’re going… or want to go. It’s much more logically organised and, consequently, a huge improvement over the previous design. Going hand-in-hand with this is the full implementation of the touchscreen controls to also include the main menus, the Function Menus and the monitor’s control panel display (including 14 function tiles, exposure settings, a real-time histogram, and a dual-axis level indicator).
Another first for the A7 line is a fully-articulating rear screen – obviously a big plus for videographers who often have more need for a wider range of adjustments. The panel itself is a 3-inch TFT LCD display with a resolution of 1.44
If the A7S III didn’t have any video capabilities – and perhaps wore a Leica badge – we’d be hailing it as the thinking photographer’s mirrorless camera.
million dots and adjustable for brightness. The EVF steps up to a 0.6-inch OLED panel with an impressive 9.44 million dots resolution and 0.9x magnification, making it easily the bestlooking electronic viewfinder we’ve seen to date… and the most comfortable to use. It’s adjustable for both brightness and colour balance.
The live view screen can be configured with a guide grid (selected from a choice of three), and a zebra pattern to indicate areas of overexposure (with adjustable levels set between 70 and 100+), plus you can cycle between a real-time histogram and a dual-axis level indicator.
The battery is Sony’s high-capacity, 2,280mAh NP-FZ100 lithium-ion pack which gives a claimed shot count of
600 when using only live view and 510 with the EVF. The A7S III is compatible with the VG-C4EM battery grip (as also used by the A9 II and A7R IV) that can hold two NP-FZ100 packs and essentially doubles the range. Plus, the batteries can be recharged in-situ via the camera’s Type-C USB connection. The USB-C port also supports tethered shooting. The other interfaces are HDMI Type A (full size), microUSB 2.0, and 3.5mm audio in and audio out minijacks. The wireless connections are Wi-Fi with NFC (supporting both the 2.4 and 5GHz bandwidths) and Bluetooth LE.
Speed And Performance
Using a Sony 80GB CFexpress Type A memory card and the mechanical shutter, the A7S III captured a burst of 105 JPEG/large/ extra-fine files in 10.525 seconds, representing a shooting speed of 9.97fps – obviously as close to 10fps as makes no difference. Out of interest, we also ran a time trial using a Panasonic 64GB SDXC UHS-II V90 speed card, and a sequence of 64 best-quality JPEGs was recorded in 6.455 seconds, giving a shooting speed of 9.91fps. So you don’t lose any speed with the fastest SD cards, but burst lengths are reduced. Test files averaged 8.75MB in size.
Sony’s continued development of its Fast Hybrid autofocusing puts it on par with the best that’s available in mirrorless cameras. Canon’s Dual Pixel CMOS AF II has set the standard, but Sony is mounting a serious challenge and you’d have to say the A7S III’s tracking performance – which is unerringly accurate in any situation when using face/eye detection – is on par with what we’ve experienced in the EOS R5 and R6. Even fast or erratically-moving subjects are kept in sharp focus no matter how much the speed or direction change, so sports and action photography would definitely be a potential application… especially since it’s all still working brilliantly at 10fps. And the low-light performance is superlative too, so this camera still autofocuses reliably in situations where the human eye is starting to struggle to discern details.
The imaging performance is equally impressive and there’s a certain tonality – related to the big pixel size – that’s very appealing visually. The best-quality JPEGs look superb in terms of colour reproduction, contrast and gradation, and it’s hard to fault either the detailing or definition. There will be a limit to how large these files can be reproduced, but it’s unlikely to be an issue unless you’re thinking of making exhibition prints and, even then, we suspect everything would hold together pretty well. The wide dynamic range translates into huge exposure latitude so, with RAW files, there’s up to four stops of get-out-of-jail exposure correction… the shadows easily being brightened without any discernible noise. In practical terms, this means you can happily underexpose in the camera to keep tonality in even the brightest highlights. While the Creative Looks and Picture Profiles presets are mainly cinematic in emphasis, there’s some great options to explore with still photography and experiment with tonality, saturation and contrast.
The really big deal with the A7S III, however, is its high ISO performance and here it’s without peer in either mirrorless cameras or DSLRs. There’s been some conjecture than the sensor might have dual-gain circuitry because the noise levels actually appear to drop at around ISO 16,000 and beyond, but it’s hard to see Sony having any sound reasons not to admit to it if this was indeed the case. We tend to think it’s something to do with how the noise reduction algorithms are being tweaked when there’s already such a high signalto-noise ratio. Regardless, the A7S III looks just as good at ISO 12,800 as it does at ISO 400, and there’s a minimal loss of either definition or saturation all the way to ISO 51,200. Grain starts to manifest itself at ISO 102,400 and there’s a noticeable softening of finer details, but these are still useable images provided you don’t want to make really big prints. Along with the IBIS and an ultra-fast prime – of which there are now plenty in the FE mount from Sony and others such as Sigma – you won’t ever need to be afraid of the dark again.
If the A7S III didn’t have any video capabilities – and perhaps wore a Leica badge – we’d be hailing it as the thinking photographer’s mirrorless camera. However, because its primary market is video-makers and Sony touts its higher-res models to photographers, it’s flying under the radar here.
Of course, there is the little matter of paying more for less in terms of resolution, which seems counter-intuitive until you consider the benefits of the bigger pixels in terms of the dynamic range, the signal-to-noise ratio and the high ISO performance. Put simply, the
A7S III is unmatched in terms of its lowlight flexibility and performance, making it a brilliant camera for street photography, but also for sports, action and wildlife. What’s more, many of the cinematic profiles and looks can work really effectively with stills, particularly if you like a softer tonality and more muted colours.
On paper alone it’s hard to make a case for the A7S III as purely a photographer’s camera. But, in practice, this case is far too compelling to ignore.