Sony’s A7 line of cameras already caters for a wide variety of applications, and with the latest A9 it’s crafted a compelling proposition for the sports and action photographer. So how exactly does this latest model differ from one of its most popular existing options, the A7R II? Let’s find out.
Design and ergonomics
The A9 is unmistakably an A-series model, although Sony has made a few important changes from what we've seen before to better serve its target user.
On the back, the A9 sports an AF joystick to help you shift the focusing point more easily, and it’s made good use of space on the top plate with an additional dial to quickly change between shooting options, together with a collar underneath it to alternate between focusing modes. On the back, there’s also an AF-ON button where the thumb rests and the rear control dial is also a little larger.
Sony Alpha A7R II
Sony Alpha A9
By contrast, the A7R II devotes this space on its top plate to just a pair of speakers and features an AF/MF control with an AEL button in place of the A9’s joystick.
The two share almost identical dimensions and there’s only around 50g or so difference in weight when each is loaded with a battery and memory card, although the A9 offers two SD-type card slots, whereas the A7R II makes do with just one.
The A9 also manages to squeeze in LAN and flash sync ports next to the same HDMI, USB, mic and headphone ports that also appear on the A7R II.
Sony Alpha A7R II
Sony Alpha A9
The rear LCD screen on each model can be adjusted in the same way as the other although the A9’s display has the advantage of touch operation.
Its 1. 44milion-dot resolution is also slightly higher than the 1. 23million-dot resolution of the A7R II’s screen, although such a small gain may be difficult to appreciate. The revised menu system on the A9 will also please those who found previous Sony menu systems, such as that on the A7R II, awkward to navigate.
Image Quality
With the A9 very much designed for speed and the A7R II for resolution, Sony has understandably fitted each with a completely different sensor.
The A7R II features a 42. 4MP full-frame CMOS sensor whereas the newer A9 opts for a 24. 2MP alternative. Both sensors are based on a back-illuminated construction for better light gathering performance, although the A9’s sensor has a stacked construction with integral memory to help it achieve its speed advantages, together with a newer version of Sony’s BIONZ X processing engine to work with.
The A9 also has a marginally broader ISO range, with a native span of ISO 100-51,200 expandable to ISO 50–204,800 when shooting stills, next to the A7R II's ISO 100-25,600 range that expands to ISO 50–102,400.
Sony Alpha A7R II
Sony Alpha A9
Both bodies are equipped with five-axis image stabilisation systems, but can also work in partnership with lens-based ones, although one point of difference is that Sony claims a maximum five stops of effectiveness for the A9’s system, against the A7R II’s still very respectable 4. 5 stops.
Special Features
Given that each model is designed with different intentions, it follows that each arrives with its own range of tricks.
Impressively, the A9 is able to fire at 20fps at full resolution, with autofocus and auto-exposure working throughout. Its ace card, however, is that it can combine this with a brand new autofocus system.
It boasts an hybrid AF system with 693 phase-detect points that are spread across approximately 93% of the frame and 25 contrast-detect points alongside, with a working range that drops to-3EV.
The A7R II, meanwhile, also features a hybrid AF system, although here it offers 399 phase-detect AF points covering 45% of the frame, and 25 contrast-detect AF points on top of it, with its working range a slightly lower -2EV.
Sony Alpha A7R II
Sony Alpha A9
The A7R II’s 5fps burst shooting rate is far slower too, but given its target audience this is entirely expected.
The A9 also sports a higher resolution viewfinder, with 3. 7million dots next to the A7R II’s 2. 4million dots. This mirrors the resolution of the viewfinders inside the recent Panasonic Lumix GH5 and Fujifilm GFX 50S (and slightly older models such as the Leica Q), but the big news here is that there is no blackout when shooting at 20fps, with refresh rates of up to 120fps.
The A7R II’s battery life is something of a weakness, with only around 290 frames per charge when using the viewfinder and 350 frames with the LCD. The A9 races ahead here, with 480 shots using the viewfinder and 650 when using the LCD.
Video Quality
Both cameras record 4K UHD video (3840 x 2160pixels) and both are equipped with headphone and microphone ports.
The A9 shoots with full-pixel readout without pixel binning, oversampling so that 6K worth of footage is condensed down to 4K output. Sony also claims the newly developed image sensor helps to reduce rolling shutter.
Sony Alpha A7R II
Sony Alpha A9
The A7R II can capture footage using the full width of the sensor (with pixel binning) or at a Super 35mm crop option, and in the latter mode captures around 5K worth of footage before reducing it down to 4K. The A7R II is also the only model out of the two to have an SLog2 option.
Conclusions
The differences between the sensors, burst rates and AF systems of these two cameras mean they end up being quite different propositions from one another, so they are unlikely to be found on the same shortlist.
Perhaps the main thing that separates the two right now, however, is price. You can get two A7R II's for the price of a single A9 and still have enough left over for half-decent lens. For most people it will be the A7R II, or other A7 models, that make the most sense, but those currently using Nikon D5 or Canon EOS-1D series bodies will no doubt be keeping an eye on a camera like the A9 – and indeed, where the series goes from here.
. digitalrev.com2017-5-13 03:00
