If you’re trying to choose a camera, the Sony a7R IIIA and the Sony a9 II are two compelling options, even though they are targeted at somewhat different photographers. The Sony a7R IIIA is a high-resolution machine, while the Sony a9 II is a high-speed machine! They are also from slightly different generations. The Sony a9 II is from 2019, while the Sony a7R IIIA was technically released in 2021 – but it’s almost an exact copy of the older Sony a7R III from October 2017 (only the resolution of the rear LCD has been improved slightly). So, effectively, the Sony a9 II is the newer camera by about two years.
How do these two cameras stack up? Here’s what you need to know.
Sony a7R IIIA vs Sony a9 II Specifications Comparison
| Camera Feature | Sony a7R IIIA | Sony a9 II |
|---|---|---|
| Announced | April 2021 | October 2019 |
| Camera Type | Mirrorless | Mirrorless |
| Sensor Type | BSI CMOS | Stacked CMOS |
| Image Processor | BIONZ X | BIONZ X (front-end LSI) |
| Resolution | 42.4 MP | 24.2 MP |
| Pixel Dimensions | 7952×5304 | 6000×4000 |
| Sensor Dimensions | 35.9 x 24.0 mm (Full Frame) | 35.6 x 23.8 mm (Full Frame) |
| Sensor Pixel Size | 4.51µ | 5.9µ |
| Low Pass Filter | No | Yes |
| IBIS (In-Body Image Stabilization) | Yes | Yes |
| Base ISO | ISO 100 | ISO 100 |
| Max Native ISO | ISO 32,000 | ISO 51,200 |
| Extended ISOs | ISO 50-102,400 | ISO 50-204,800 |
| High-Resolution Sensor Shift | Yes | No |
| Focus Stack Bracketing | No | No |
| Pre-Shoot Burst Mode | No | No |
| Fastest Shutter Speed | 1/8000 | 1/32000 |
| Longest Shutter Speed | 30 seconds | 30 seconds |
| Continuous Shooting (Mechanical Shutter) | 10 FPS | 10 FPS |
| Continuous Shooting (Electronic Shutter) | 10 FPS | 20 FPS |
| Notes for High FPS Shooting | Compressed 12-bit raw at 10 FPS (uncompressed 14-bit raw is available at 6 FPS) | Compressed 12-bit raw at 20 FPS (uncompressed 14-bit raw is available at 12 FPS) |
| Buffer Size (Raw) | 76 frames (10 FPS) | 239 frames (20 FPS) |
| Autofocus System | Hybrid PDAF | Hybrid PDAF |
| Autofocus Points | 399 | 693 |
| Low-Light AF Sensitivity (f/2 Lens, ISO 100) | -3 EV | -3 EV |
| Standard Flash Sync Speed | 1/250 | 1/250 |
| Curtain to Protect Sensor at Shutdown | No | Yes |
Video Features | ||
| Maximum Video Bit Depth (Internal) | 8 bits | 8 bits |
| Maximum Video Bit Depth (External) | 8 bits | 8 bits |
| Raw Video | No | No |
| 4K Maximum Framerate | 30 FPS | 30 FPS |
| 1080P Maximum Framerate | 120 FPS | 120 FPS |
| Additional Video Crop Factor | No | No |
| Chroma Subsampling | 4:2:0, 4:2:2 (External) | 4:2:0, 4:2:2 (External) |
| Video Recording Limit | 30 min | 780 min |
Physical and Other Features | ||
| Card Slots | 2 | 2 |
| Slot 1 Type | SD (UHS-II) | SD (UHS-II) |
| Slot 2 Type | SD (UHS-I) | SD (UHS-II) |
| Rear LCD Size (Diagonal) | 3.0 in | 3.0 in |
| Rear LCD Resolution | 2.36 million dots | 1.44 million dots |
| Articulating LCD | Single Axis | Single Axis |
| Touchscreen | Yes | Yes |
| Viewfinder | EVF | EVF |
| Viewfinder Magnification | 0.78x | 0.78x |
| Viewfinder Resolution | 3.69 million dots | 3.69 million dots |
| Viewfinder Coverage | 100% | 100% |
| Voice Memo | No | Yes |
| 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 C 3.2 Gen 1 | Type C 3.2 Gen 1 |
| Battery Type | NP-FZ100 | NP-FZ100 |
| Battery Life (Viewfinder) | 530 frames | 500 frames |
| Battery Life (Rear LCD) | 640 frames | 690 frames |
| Weather Sealed | Yes | Yes |
| Weight (Body Only w/ Battery + Card) | 657 g (1.45 lbs.) | 678 g (1.49 lbs.) |
| Dimensions (LxHxD) | 127 x 96 x 74 mm (5.0 x 3.8 x 2.9″) | 129 x 96 x 78 mm (5.1 x 3.8 x 3.1″) |
Price Comparison | ||
| MSRP, Body Only | $2200 (Check Current Price) | $4500 (Check Current Price) |
| Used Prices | Sony a7R IIIA Used Prices | Sony a9 II Used Prices |
As you can see from the specifications above, the Sony a9 II is definitely the higher-end camera. That shouldn’t be a surprise, considering that it’s more than twice the price and essentially two years newer (again, because the a7R IIIA is a carbon copy of the old a7R III).
The biggest differences in favor of the Sony a9 are the faster burst rate of 20 FPS, the substantially larger buffer (more than 3x larger), and the more advanced autofocus system. All of these benefits are significant for sports photography, wildlife photography, and any fast-moving action.
But even though the Sony a7R IIIA is the slower camera based on older technology, it does have an important trick up its sleeve: resolution! The Sony a7R IIIA has a 42 megapixel sensor, and it even has a sensor-shift mode than can record full RGB data per pixel, giving you more detailed photos (even though the actual resolution of 42 megapixels doesn’t change). In short, the Sony a7R IIIA is capable of capturing significantly more detail than the Sony a9 II. But keep in mind that the pixel-shift mode itself has some limitations.
Summary and Recommendations
If both of these cameras were exactly the same price, the answer would be obvious. Get the Sony a7R IIIA if you need to maximize your resolution even at the expense of everything else. Otherwise, get the Sony a9 II. The a9 II is a faster, more advanced camera with a better autofocus system and a variety of newer features. It’s the better camera for anything other than high-resolution applications.
However, the Sony a7R IIIA and Sony a9 are far from the same price! The original MSRP of the a9 II is $4500 – more than double the $2200 MSRP of the a7R IIIA. Granted, the two cameras are closer in price on the used market, but the a9 II is still clearly more expensive.
With that context in mind, my general suggestion is to get the Sony a9 only if you’re photographing fast-moving wildlife or sports subjects. Otherwise, you can find less expensive cameras that will perform similarly. The a7R IIIA is one such camera, but you could also consider cameras in Sony’s a7 or a7C lineups, among others.
What does the Sony a7R IIIA offer over the Sony a9 II?
- 1.75 times more megapixels (42.4MP vs 24.2MP)
- Much lower price, costing $2300 less—you could take a trip with this savings!
What does the Sony a9 II offer over the Sony a7R IIIA?
- More advanced autofocus system and faster burst rate of 20 FPS (rather than 10 FPS)
- Bigger buffer for shooting long bursts of photos
- Useful voice memo feature for quickly labeling your photos in the field
Questions? Go to our forum, where you can start a conversation and talk to photographers about these two cameras!
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