The Sony a9 and the Sony a7S III may both be full-frame Sony cameras, but that’s about where the similarities stop! They are totally different cameras aimed at different photographers. They’re also from separate generations – the Sony a9 was launched in April 2017, while the Sony a7S III was launched in July of 2020. Nevertheless, if you’re wondering how the two cameras stack up, here’s what you need to know.
Sony a9 vs Sony a7S III Specifications Comparison
| Camera Feature | Sony a9 | Sony a7S III |
|---|---|---|
| Announced | April 2017 | July 2020 |
| Camera Type | Mirrorless | Mirrorless |
| Sensor Type | Stacked CMOS | BSI CMOS |
| Image Processor | BIONZ X | BIONZ XR |
| Resolution | 24.2 MP | 12.1 MP |
| Pixel Dimensions | 6000×4000 | 4240×2832 |
| Sensor Dimensions | 35.6 x 23.8 mm (Full Frame) | 35.6 x 23.8 mm (Full Frame) |
| Sensor Pixel Size | 5.93µ | 8.4µ |
| Low Pass Filter | Yes | Yes |
| IBIS (In-Body Image Stabilization) | Yes | Yes |
| Base ISO | ISO 100 | ISO 80 |
| Max Native ISO | ISO 51,200 | ISO 102,400 |
| Extended ISOs | ISO 50-204,800 | ISO 40-409,600 |
| High-Resolution Sensor Shift | No | No |
| Focus Stack Bracketing | No | No |
| Pre-Shoot Burst Mode | No | No |
| Fastest Shutter Speed | 1/32000 | 1/8000 |
| Longest Shutter Speed | 30 seconds | 30 seconds |
| Continuous Shooting (Mechanical Shutter) | 5 FPS | 10 FPS |
| Continuous Shooting (Electronic Shutter) | 20 FPS | 10 FPS |
| Notes for High FPS Shooting | Compressed 12-bit raw at 20 FPS (uncompressed 12-bit raw is available at 12 FPS) | None |
| Buffer Size (Raw) | 241 frames (20 FPS) | Over 1000 frames (10 FPS) |
| Autofocus System | Hybrid PDAF | Hybrid PDAF |
| Autofocus Points | 693 | 759 |
| Low-Light AF Sensitivity (f/2 Lens, ISO 100) | -3 EV | -6 EV |
| Standard Flash Sync Speed | 1/250 | 1/250 |
| Curtain to Protect Sensor at Shutdown | No | No |
Video Features | ||
| Maximum Video Bit Depth (Internal) | 8 bits | 10 bits |
| Maximum Video Bit Depth (External) | 8 bits | 16 bits |
| Raw Video | No | Yes, externally |
| 4K Maximum Framerate | 30 FPS | 120 FPS |
| 1080P Maximum Framerate | 120 FPS | 240 FPS |
| Additional Video Crop Factor | 1.2x crop at 4K 30p (4K 24/25p has no additional crop) | 1.1x crop at 4K 120p (otherwise no additional crop) |
| Chroma Subsampling | 4:2:0, 4:2:2 (External) | 4:2:2 |
| Video Recording Limit | 30 min | 780 min |
Physical and Other Features | ||
| Card Slots | 2 | 2 |
| Slot 1 Type | SD (UHS-II) | CFExpress Type A, or SD (UHS-II) |
| Slot 2 Type | SD (UHS-I) | CFExpress Type A, or SD (UHS-II) |
| Rear LCD Size (Diagonal) | 3.0 in | 3.0 in |
| Rear LCD Resolution | 1.44 million dots | 1.44 million dots |
| Articulating LCD | Single Axis | Fully Articulating |
| Touchscreen | Yes | Yes |
| Viewfinder | EVF | EVF |
| Viewfinder Magnification | 0.78x | 0.90x |
| Viewfinder Resolution | 3.69 million dots | 9.44 million dots |
| Viewfinder Coverage | 100% | 100% |
| Voice Memo | No | No |
| Headphone Jack | Yes | Yes |
| Microphone Jack | Yes | Yes |
| Built-in Flash | No | No |
| GPS | No | No |
| Bluetooth | Yes | Yes |
| WiFi | Yes | Yes |
| USB Type | Type B 2.0 | Type C 3.2 Gen 1 |
| Battery Type | NP-FZ100 | NP-FZ100 |
| Battery Life (Viewfinder) | 480 frames | 510 frames |
| Battery Life (Rear LCD) | 650 frames | 600 frames |
| Weather Sealed | Yes | Yes |
| Weight (Body Only w/ Battery + Card) | 588 g (1.30 lbs.) | 699 g (1.54 lbs.) |
| Dimensions (LxHxD) | 127 x 96 x 73 mm (5.0 x 3.8 x 2.9″)1 | 129 x 97 x 81 mm (5.1 x 3.9 x 3.3″) |
Price Comparison | ||
| MSRP, Body Only | $4500 (Discontinued) | $3500 (Check Current Price) |
| Used Prices | Sony a9 Used Prices | Sony a7S III Used Prices |
| 1The Sony a9’s official dimensions do not include the depth of the protruding viewfinder. To match typical standards today, 10mm were added to the a9’s depth measurement in this table. | ||
The Sony a7S III is the newer camera, and that really shines through in this comparison! It matches or beats the Sony a9 almost everywhere you look. But there are two major advantages of the Sony a9: the higher resolution, and the 20 FPS burst mode.
Starting with resolution, don’t get me wrong – the Sony a7S III’s 12-megapixel sensor is beloved by many photographers, and especially videographers. It’s extremely good in low light situations, particularly high-ISO videography. Nevertheless, 12 megapixels is quite low in today’s world. If you want to print large or crop extensively, the Sony a9’s 24 megapixel sensor definitely has appeal.
Then there’s the burst rate. Although the Sony a7S III has a solid maximum rate of 10 FPS, the Sony a9 doubles it to 20 FPS. That could make the difference in fast-paced sports and wildlife photography, even though 10 FPS is already enough for all but the fastest subjects.
Those two differences don’t change the obvious: the Sony a7S III is clearly the higher-end camera here. It’s mostly bad news in the Sony a9’s column above. But if you need 24 megapixels and/or a higher burst rate, the various other advantages of the a7S III may not matter very much to you.
Summary and Recommendations
Let’s start with the obvious situation: videography. If you expect to film a lot of video with your camera, there’s no question whatsoever – the Sony a7S III is a much better camera than the Sony a9.
The situation gets a bit trickier for sports and wildlife photography. Yes, the Sony a7S III has the edge in buffer capacity, low-light performance, and even autofocus system (although they’re both excellent in that department). But if you plan to crop your photos extensively, 12 megapixels may not be enough. And if you want a higher burst rate, the 20 FPS spec of the Sony a9 is hard to ignore. I lean in the a9’s direction here, but I also think you could go either way.
As for something like landscape photography, neither of these cameras is necessarily the right choice; I’d prefer something from Sony’s a7 or a7R series instead. But strictly between these two cameras, the a9 wins that comparison just because of the higher resolution sensor. Milky Way photographers, however, should consider the a7S III because of its fantastic low-light performance.
Overall, the Sony a7S III is the more advanced camera in this comparison, and that’s reflected in the used prices of the two cameras (you’ll save quite a bit if you go with the a9). That said, the a7S III is also a more specialized camera and not for everyone because of the 12 megapixel sensor. Hopefully that answers your questions, and now you know which of these cameras is the right choice for you!
What does the Sony a9 offer over the Sony a7S III?
- Twice as many pixels (24.2 MP vs 12.1 MP)
- Faster maximum burst rate of 20 FPS rather than 10 FPS
- Lighter weight (111 g lighter)
What does the Sony a7S III offer over the Sony a9?
- Faster processor with a bigger buffer and a newer, improved autofocus system
- Substantially better video features, including slow-motion 4K and external raw video recording
- Better performance at ultra-high ISO values, especially in video
Questions? Go to our forum, where you can start a conversation and talk to photographers about these two cameras!
Photography Life is part of the KEH and B&H affiliate programs. When you make a purchase through the affiliate links in this article, we can be compensated with a percentage of each sale. If you found this comparison useful, buying anything through these links allows you to support Photography Life at no extra cost to you. Thank you for supporting our efforts!
