Sony a7R II review - Full frame and 4K in one

When rumours first circulated that Sony was developing a full-frame compact system camera (CSC) using the same E-Mount system as its existing cropped-sensor range, I must admit I thought it was far-fetched. However the Alpha a7 turned out to be very real and an unbridled success, delivering full-frame quality in a petite body and at a temptingly low price. The a7R II reviewed here is one generation newer and one step up the range. At £2,599 body-only it’s the most expensive CSC to date, but there are some compelling reasons to justify it.

A full-frame sensor sets high expectations for image quality, and this one’s 42-megapixel resolution and back-illuminated design bodes well for detail and noise levels respectively. A maximum ISO speed of 102,400 shows that Sony has a lot of confidence about this sensor’s noise levels. There were only five compatible lenses when the a7 and a7R first landed, but now there are 11, including a 24-240mm zoom and primes at 28mm, 35mm, 55mm and 90mm. That’s still a long way short of the lens ranges for other full-frame cameras, but in my mind it’s not a significant drawback.

Five-axis image stabilisation is built into the sensor, which means it works with any lens. Video recording is at resolutions up to 4K, while 1080p capture comes at a wide range of frame rates up to 120fps. The electronic viewfinder (EVF) is as big and detailed as they come with its 1,024x768 resolution and 0.78x magnification. The 3in LCD screen tilts up and down for easy viewing at elbow or above-head height. This is particularly useful for CSCs, which – unlike SLRs – work just as well with their LCD screens as their viewfinders.

One area where the a7R II falls short is for battery life, managing 340 shots when using the LCD screen and just 290 shots with the viewfinder. Video recording lasts for just 50 minutes per charge. A full-frame, high-resolution sensor requires a lot of juice but a larger battery would have required a larger camera body. We like how this magnesium alloy-clad camera weighs in at 625g, and appreciate Sony’s decision to include two batteries in the box. Charging is either in-camera or with the supplied charger.

Wi-Fi is pretty much standard issue on cameras these days, but this implementation deserves a mention because of its elegant simplicity. While browsing photos on the camera, simply holding the camera to an NFC-equipped Android device made them connect and transfer a 2-megapixel copy the current photo, all in about seven seconds. Other Wi-Fi cameras can perform various impressive tricks but this is the function I use far more than any other, so it’s great that Sony has made it so easy. The remote shooting function isn’t so impressive, with control over exposure compensation and self-timer but no autofocus control.

Speed and autofocus

Any camera at this price needs to be responsive but the huge resolution places high demands on the camera’s processor. It came in at 4.8fps in continuous mode – not far short of the 5fps claimed speed but slower than many cheaper CSCs. It kept going for 21 frames in RAW mode and 24 for JPEGs, although changing the JPEG quality setting from X Fine to Fine increased this to 35 frames. I was able to adjust settings while it was saving images, but not access the menu.

Autofocus was consistently responsive, taking around 0.3 seconds between pressing the shutter button and capturing a photo. Accuracy wasn’t as high as I’d like, though, with roughly one in ten shots exhibiting slightly soft focus. To a certain extent this is a hazard for any full-frame camera as the depth of field is that much shallower. However, the a7R II doesn’t appear to be as successful as SLRs at this price at tracking and pre-empting moving subjects. Along with the modest 5fps burst speed and the lack of ultra-telephoto lenses, it seems fair to say this isn’t a camera that’s ideally suited to action photography.

The autofocus options are reasonably easy to access, with the ability to move the autofocus area using the navigation pad and to cycle through the various modes using the rear wheel. The centre button invokes Eye AF, whereupon the camera uses face detection to focus on the subject’s eyes. A common feature among upmarket SLRs is to focus using an AF On button rather than by half-pressing the shutter button. It’s possible to assign a customisable button to this task but none is ideally located for this. I’ve become accustomed to using a touchscreen to move the autofocus point, and a few recent cameras allow this even when composing shots with the viewfinder. Sadly, the a7R II’s screen isn’t touch-sensitive. At least it’s articulated for shooting at awkward angles – something very few full-frame cameras offer.

The other controls are well laid out, with dual command dials for shutter speed and aperture control and a generous quota of customisable buttons. I didn’t regret not having a passive LCD screen on the top plate – the dedicated exposure compensation dial holds a much greater appeal. Seasoned SLR users may miss the ability to use button-and-dial combinations to access features such as ISO speed, drive mode and metering, but the controls work well enough.

Video capture

4K video is a major selling point for this camera, and rightly so. It’s recorded in XAVC S format at 60 or 100Mbit/s and 24, 25 or 30fps. 4K picture quality was outstanding, with crisp, lifelike details and cleaner colours than I saw from the Panasonic GH4 at ISO 200. Details weren’t quite as sharp as from 4K footage from the Samsung NX1 but I suspect that’s largely down to the Samsung’s more aggressive digital sharpening. Comparing the three cameras’ 4K output at ISO 3200, the Sony took a clear lead for low noise while maintaining crisp details.

4K capture uses a cropped area of the frame, although the reason isn't entirely clear. Whereas the GH4 uses a crop that means each pixel of its 4K footage relates directly to a pixel on the sensor, the a7R II’s cropped area still has a higher resolution than the 4K frame. It’s about 5,376x3,024 pixels, by my calculations. That gives a crop factor of 1.5x for 4K capture, so the effective focal length of lenses are adjusted accordingly, with 24mm becoming 36mm and so on. That’s good news for telephoto shooting but not so good for wide-angle.

1080p capture uses the full sensor width, and quality was once again excellent. There’s a wide array of frame rates from 24 to 120fps, but no slow motion options. You could always slow 120fps footage down in editing software, but it’s a bit annoying that switching between PAL and NSTC frame rates requires the card to be reformatted.

Recording at high bit rates requires a fast SD card, and the camera demands that it’s UHS-I U3. I bought a suitably specified Kingston card but the camera still complained that it wasn’t suitable. Sony supplied a Sony-branded microSDXC U3 card that did the job.

Image quality

There’s less to report from my photo quality tests. The sensor excelled for both sharp details and low noise, and the metering took tricky lighting conditions in its stride. The occasional autofocus errors were the only issue I noticed, but taking a couple of shots of each subject – which is always worth doing – provided an effective solution.

Compared to its full-frame rivals, there isn’t much to choose between the a7R II and the Canon EOS 5Ds for details, noise levels or dynamic range, but the Sony nudged into the lead for noise levels in JPEGs at ISO 12800 and above. The Canon’s ISO speed doesn’t go any higher but the Sony continues all the way up to 102,400. ISO 25,600 is probably a sensible limit in practice. The Nikon D750 and Sony a7 exhibited less noise at ISO 12800 and above, but that’s not surprising considering their relatively modest 24-megapixel resolutions.

Ultimately, there’s not much to choose between the current generation of full-frame cameras for image quality, but the a7R II is comfortably up there with the best.

^ Sharp focus, carefully controlled highlights and plenty of definition to the dense background – a great result. (1/200s, f/8, ISO 100, 39mm)

^ Another well-judged automatic exposure, but this high-contrast scene reveals some slight chromatic aberrations. They’re undetectable at normal viewing sizes, though. (1/500s, f/8, ISO 100, 53mm)

^ An f/1.4 lens on a full-frame camera gives a fantastically shallow depth of field. Automatic metering has kept highlights on the subject just short of clipping. (1/640s, f/1.4, ISO 100, 35mm)

^ Program mode doesn’t like to venture beyond f/2, but I can’t fault this shot on automatic settings. (1/60s, f/2, ISO 160, 55mm)

^ It’s starting to get grainy at ISO 10,000 but it's not intrusive. (1/60s, f/3.5, ISO 10,000, 24mm)

Conclusion

It’s hard to rate the a7R II because there’s not much to compare it with. It’s one of only two cameras to offer 4K video from a full-frame sensor – the other one is the Canon EOS 1D C, and it costs £5,650. As such, the Sony is a superb choice for people who want the best quality available for both photography and video. £2,599 is still expensive, though, and I suspect that many people would be satisfied by either the Nikon D750, the Samsung NX1 or the Panasonic GH4, which cost around £1,500, £1,150 and £1,000 respectively. The Sony a7 is still available for £800 body-only – a phenomenal price for a full-frame camera. Those who are happy to spend more may be better off investing in lenses.

Still, there’s no denying the allure of a full-frame camera, and 4K video is a big draw, too. If you don’t want to compromise on either, the A7R II is the obvious choice.