Sony is now one of the top (if not the top) mirrorless camera brands for photographers. With so many models out now (and all of them pretty great), it can be really tricky figuring out which Sony mirrorless camera is truly the right one for you.
There are 18 mirrorless camera bodies to choose from Sony but we’re only going to cover the three newest (as of this writing) models. They are three incredible systems, so there is no right or wrong choice. But they do each have their specialties. The a7 III, a7R IV, and a9 II are full frame Sony mirrorless cameras using the E mount lens system. Let’s get into the details…
Sony Mirrorless Camera Sensors
Sony sensors are dominating the industry and boast extremely high scores on sites like DxOMark. All three of our recommended Sony mirrorless camera bodies have full frame sensors. That is basically where the sensor similarities end though:
• The a7 III sensor is a 24 megapixel Exmor R CMOS sensor. This sensor has a back-illuminated structure so it is able to produce high-speed capture at very low noise ratios.
• The a7R IV sensor is a massive 61 megapixel Exmor R CMOS sensor. This sensor is also backlit, produces high sensitivity to light, but definitely exhibits more noise at higher ISOs than the a7 III or a9 II. However, you won’t be disappointed even at an ISO of 6400.
• The a9 II sensor is 24 megapixel Exmor RS CMOS sensor. The ’S’ designation here is for speed. This sensor has an integrated memory layer that is basically an initial memory buffer. This helps with the frames per second shooting speeds, which we will discuss next.
So how does this help you make a buying decision?
With a Sony mirrorless camera, it almost doesn’t matter. Yes, the a7R IV is a bit worse in the noise production department, but all three of these cameras produce very publishable photos. With added noise processing adjustments in Lightroom or Capture One, you can push all three to ISO 12,500 easily!
So the sensor you choose would really be dependent on your intended subject matter. Are you making massive wall-sized prints? Then you want the a7R IV. Are you just starting out in photography and on a budget – or want something super well-rounded? Then you want the a7 III. Are you shooting Formula 1? Yep, you guessed it – get the a9 II.
Not satisfied with these simplistic recommendations? Read on – the decision-making agony continues with our next features…
Frames Per Second Shooting Speeds (Sony a9 II Clear Winner)
The a7 III and a7R IV both shoot at a whopping 10 FPS in high speed drive mode. The a9 II doubles this to give you 20 FPS with a silent electronic shutter and 10 FPS when using the mechanical shutter. What’s more, the a9 II has an upgraded second card slot rated for UHS-II cards. This means less chance of slow-down when shooting bursts with dual cards. The a7R IV has this, too, but the a7 III does not (the a7 III has one UHS-II slot and one slower UHS-I slot). Learn more about the importance of cards and card slot types in our Memory Card Basics post.
The a9 II will get you about 130 Raw images in a burst before the buffer forces you to take a break (about half that with the a7R IV and a7 III but that’s still super great) . On the a7R IV, shooting uncompressed Raw will drop your effective FPS down to a relatively-sluggish 7 FPS. The a7 III stays closer to spec at 9.7 FPS. I’d say that the a7 III and even the a7R IV are suitable for events like weddings, but if you’re big on sports and wildlife, spring for the a9 II.
Small Differences in Autofocus and Composing/Monitoring
From the standpoint of autofocus speed, all 3 cameras autofocus-track at their corresponding frame rates. However, the a7 III and a9 II have autofocus points covering 93% of the viewfinder and the the a7R IV only has 87% coverage. Which, if you think about it, is pretty amazing because you are shooting a 61 megapixel file. How these compare in the specs:
a7 III: 425 contrast AF points with a 693-point phase-detection AF system
a7R IV: 425 contrast AF points with a 567-point phase-detection AF system
a9 II: 425 contrast AF points with a 693-point phase-detection AF system
What does this mean? Contrast AF looks for edges in the scene and focuses until the edge contrast is hard (or “sharp”). It’s relatively slow and can cause focus hunting – something you’ve probably experienced with great frustration. This can also drain your battery. It’s highly accurate with still subjects but is simply too slow a lot of the time for moving subjects. Phase detection is more of a “split prism” approach to focusing (just without the prism). It’s a little like focusing with a rangefinder, only you’re not having to do it – the camera is doing it for you. Phase detection takes in light and divides it, analyses it for similar light patterns, calculates position, and then somehow communicates all of this in fractions of a second so that you nail the exact right amount of focus at the right time. I promise it’s science but it sure feels like magic. There are weaknesses with both, so a hybrid system like what you find with Sony mirrorless cameras is best.
Get Used to Electronic Viewfinders
All three cameras perform admirably in this area. All three let you lock on a subject’s eye, all have tactile joysticks for quick AF point adjustments, all have -3 to +20 EV sensitivity and touch-to-focus action on the large LCD. Speaking of the LCD, all three cameras have 3″ touchscreens with 180º tilt but overall resolution is higher in the a9 II and a7R IV. The viewfinders are different in all three of these cameras. The a7R IV boasts an UXGA OLED 5.76 million-dot resolution, the a9 II has a Quad-VGA OLED with a 3.68 million-dot resolution, and the a7 III has the lowest resolution viewfinder, using an XGA OLED with “only”a 2.35 million-dot resolution. These details are important because, after all, what good is AF performance if you’re not even comfortable with the aspects of the camera that allow you to compose and monitor the scene?
Comfort is big here because if you’re just now exploring mirrorless after being on the DSLR train for years, you might hate the electronic viewfinders (at first). An EVF is less like looking through a window and more like looking at a TV. This is where maybe renting a mirrorless camera is essential because some people take to EVFs right away and others just never get used to them. They show your settings, exposures, and preview images in near-real time – an awesome alternative to “chimping” on a DSLR. But it’s hard to beat the feeling of really seeing the scene like what you get with the pentaprism system of DSLRs. Know that not all EVFs are created equally (as evidenced from the specs above) so don’t just rent the cheapest mirrorless as a test – rent the thing you’d really consider buying later. EVFs are also fairly customizable so you’ll need to tweak the settings until you get something you love.
In short, the a7R IV has a (very slightly) less robust phase-detection system but when you’re shooting mostly products, portraits, and landscapes (all of which really make great use of the huge file sizes this camera produces), then that is fine. The heavy AF lifting comes from wildlife and sports, which the a9 II excels at anyway. The a7 III – Goldilocks style – is in the middle.
Small But Important Video Differences
All three cameras shoot 4K30p with full pixel readout in Super 35mm mode with 8-bit depth and 4:2:0 color (4:2:2 externally). There are some small differences that might be important to you. The a7R IV has unlimited recording limits (limited by your card capacity and battery life). The a7 III and a9 II may get this, too, in a firmware update but right now the a7R IV already has it. For the other two, the limit sits at just shy of 30 minutes. A firmware release added Real Time Eye AF for video in the a7 III (it was already in the other two). The a9 II lacks S-Log while the a7 III lacks the enhanced MI shoe, which gives you the option of attaching an ECM-B1M shotgun mic for recording digital audio directly to the file when filming.
The a7 III and a7R IV both capture 6K and downsample to 4K, though you’re starting from more megapixels overall with the a7R IV. The Super 35mm modes also vary slightly between the a7 III and and a7R IV – the former uses a 1.5x crop while the latter uses a 1.6x crop at 24 FPS and 1.8x at 30 FPS. You can capture footage externally and internally simultaneously with all three cameras and all three have microphone and headphone ports.
Consensus? For the unlimited recording limits and overall resolution, the a7R IV edges out the other two – though that is not to say the other two aren’t great (though the Sony a9 II seems the least suited to being video-dedicated vs the others).
Body and Other Little Details
These Sony mirrorless cameras are all so great that it makes the little differences even more important when choosing the right one for you. Shooting prowess is not really the issue since they are all top cameras – the issue for you could be in certain connectivity ports, grip depths, battery life, and more. Let’s dive into these small details…
PC Sync Port
None in the a7 III. The a9 II and the a7R IV have PC terminals. This doesn’t preclude you from firing off-camera flashes with the a7 III. It’s just that you won’t be able to connect this camera directly to a strobe with a long PC cable – a handy option if there are wireless triggering issues that crop up at the last minute on set. For the a7 III, you’d have to use a PC sync hot shoe adapter or connect something like a PocketWizard or RadioPopper directly to your hot shoe, which is what most people would do anyway. So it’s not a deal-breaking omission but some people might be annoyed at the lack of a PC terminal in the a7 III, especially for backup reasons. The flash X-sync speed is the same on all three, maxing out at 1/250th of a second.
LCD and Viewfinder
We mentioned LCD and viewfinder differences already above but they are definitely worth mentioning again within the context of form factor and little details. All three cameras have 3″ tilting touchscreen LCDs but the a7 III’s has a slightly lower resolution. The viewfinders are all the same at first glance, with 100% coverage, 0.78x magnification, same diopter adjustment range, and overall size (.5″). However, the a7 III actually uses an older panel inherited from the a7 II that has a lower refresh rate. In the simplest terms, the higher the refresh rate, the smoother the scene will look to you when composing. For example, when shooting sports and panning with a camera that uses an older EVF, you might witness jagged results that mess with you when trying to shoot. A “slow” refresh rate for an EVF is considered to be around 30 FPS. The a7 III offers an admirable 60 FPS. But the a7R IV and a9 II are upwards of 120 FPS.
A/V Connectivity Ports
All three cameras are equipped with USB 3.1 (Gen 1 – so, 5 Gbps)/USB-C (offering both data transferring and charging capabilities) , micro HDMI (aka Micro D), a 3.5mm mic port, and a headphone port (remember, the a7 III doesn’t offer the advanced MI shoe for the new digital external mics Sony offers). With that HDMI port, you can get clean video out (no camera overlays or settings info getting in the way) to an external recorder. You can record 4K footage on an SD and to an external recorder simultaneously and you have access to TimeCode out. None of these cameras have built-in GPS.
Ergonomics and Build
The Sony a7 III is the smallest and lightest of the three, though not by a lot. The a7R IV and a9 II both offer thicker buttons with a less “spongy” press-feel and also bigger, better-textured dials (giving you increased tactile feedback, especially when wearing gloves). The deeper grip and textured joysticks of the a7R IV and a9 II are also welcome changes. If you’re holding out for a possible a7 IV (rumored for late this year), then expect to see similar ergos. The a7R IV and a9 II also have better overall weather sealing.
If you’re concerned about all this “robustness” cutting into the benefits of portability – that concern is very real, especially when paired with Sony’s rather large GM-series glass. But all these cameras are still sleeker and lighter than most DSLRs.
Here is where your budget concerns are met.
a7 III = $1,800*
a7R IV = $3,500
a9 II = $4,500
If you compare those numbers with the new Canon 1D X Mark III and Nikon D6 at $6,500, you’d still have an additional $2,000+ dollars in your pocket before starting to buy a single Sony lens. So while these cameras aren’t cheap, they are much more in-reach than some of the other brands’ flagships out there. It’s no surprise that the a7 III – the oldest of the trio – gives you the best deal. Once the a7 IV does come out, the price will get even better.
How to Choose the Best Sony Mirrorless Camera for You
Sony is leading the camera market from an options standpoint. Three full frame cameras (and that is after narrowing it down) with drastically varying price points, but all with feature sets that cover even the most demanding of pros. Sony has a lot of lens focal lengths covered at this point, so you are getting a complete photo system that competes handily with Nikon and Canon. In fact, Sony now has the lightest 600mm f/4 super telephoto lens ever made at 6.7 lbs! So they are definitely now competitive on lenses.
It all really boils down to three things to think about:
1. Price. What best fits your budget?
2. Speed. What will you be photographing? Does it require a really fast frame rate? If something like Formula One is your deal, then frame rates really matter. If not, you don’t need to spring for the a9 II.
3. File size. Need super high resolution detail? Putting massive images on a gallery wall? Then resolution is the direction you need to go and you should really go with the a7R IV.
The best part about this decision-making process is that you can rent all three camera bodies with one lens and figure out just which one works best for you!
* All quoted pricing is at the time of this writing and subject to change.
Latest posts by Jay Goodrich (see all)
- What is the Best Sony Mirrorless Camera for You? - March 24, 2020
- How to Use Your New Camera - December 26, 2019
- Favorite Lenses and Lens Focal Lengths for Landscape - October 21, 2019