The Sony Alpha 7R IV breaks the 50MP barrier, but how else does it improve on the sensational Alpha 7R III? Michael Topham investigates
Sony Alpha 7R IV Review: Performance
The image quality from the A7R III’s 42.4MP sensor was remarkable, but the 61MP images from of the A7R IV go one better. The fine detail it resolves is phenomenal, but you do need to be wary that this does draw attention to optical flaws and the slightest sign of camera shake. The good news is that the 5-axis image stabilisation is remarkably effective at ensuring the camera can be used handheld, but as a matter of principle you will want to keep your shutter speed high when using the camera unsupported.
Dynamic range is astonishing at the low end of the ISO range too, with the ability to pull out immense detail from dark shadows without excessive noise creeping in. To prevent highlights being blown out in high contrast scenes, such as in the image above, I opted to expose for the brighter parts in a scene and then process the raw file to lift the shadows and balance the exposure.
I couldn’t fault the metering system in use. It rarely misread a scene and much the same can be said for the auto white balance system. Colour is consistently faithful, resulting in images that appear neither too warm or too cool. If you end up shooting JPEGs more than you do Raws, you may wish to tweak the creative style settings. As an example, I preferred the look to monochrome images after upping the contrast to +2 in Black and White mode.
With each generation we’ve seen the A7R get faster and more responsive. Once again we’re not left disappointed by the focusing performance the A7R IV puts in. One area where it really excels is its AI-based real-time autofocus. Using it on a portrait shoot at the coast was a brilliant test and demonstrated how accurate it is at identifying a face within the frame, with the smaller of the two green AF squares revealing which eye of your subject it has locked onto.
When you’re shooting portraits with a shallow depth of field you’ll most likely want the camera to focus on the eye closest to the camera, which more often than not the camera gets rights. If it selects the wrong eye or you’d prefer to have a say in this there’s the option to specify which eye it focuses on from the AF2 menu settings. Out in the field I was very impressed by the way it faultlessly switched between focusing on the subject’s face and eye, even managing to hold focus when the model looked down, or away from the camera.
The same could be said when I attempted photographing a few dogs at a local fair after changing the subject detection from human to animal. Those who shoot pets or animals on safari using telephoto lenses will find animal Eye AF extremely useful. My only criticism, which was also mentioned in our recent Sony Cyber-shot RX100 VII review, is that animal Eye AF can’t be combined with focus tracking like it can when subject detection is set to humans.
As usual from Sony you get an array of focus area modes to choose from. In Wide mode the camera attempts to identify the subject wherever it may be in the frame, with Zone restricting it to a smaller area. In Flexible Spot mode you can position the focus point manually almost anywhere in the frame using the joystick and with Expand Flexible Spot, surrounding focus points are used to assist the camera in focusing.
Continuous focusing on fast moving subjects is very hasty. It seemed untroubled when I asked it to keep focus on a group of cyclists travelling towards the camera at speed. Although the hit rate of sharp shots in a burst might not be quite as high as you’d get on the sports and action focused Alpha 9, you can’t really fault the speed at which the A7R IV keeps up with subjects that move.
After years of putting up with the focus area being drawn in a dull mid-grey and complaining that it’s very difficult to see the AF point when subject contrast is low, Sony has finally responded with an answer. Users will welcome the option to change the focus frame colour to white or red. Although this is listed as one of the minor improvements among the changes that have been made, it makes a big difference in day-to-day operation and reiterates that Sony are acknowledging feedback and responding to it in order to make future releases even better.
The increased resolution has put a lot more demand on the A7R IV’s imaging processor to keep up, which it does remarkably well. Loaded with a 64GB SDXC UHS II Class 10 card, it had no trouble recording 70 compressed raw files or 31 uncompressed raw files to the card at 10fps before the buffer was hit. Repeating this test after I’d changed the file format to Extra Fine JPEG, resulted in 70 frames being recorded at 10fps – a high number that’ll allow sport, action and wildlife shooters to keep firing without worry of their burst being interrupted.
A drawback of the large pixel count and high resolution output is that memory cards do fill up quickly. I shot 418 Uncompressed Raw & Extra Fine JPEG images before it spilt over to using the second card in slot 2. Additionally, the large 123MB (uncompressed) and 61MB (compressed) .ARW raw files demand a lot of processing power from your computer. My 2017 2.5 GHz Intel Core i7 Macbook Pro didn’t struggle to process the files, however my 2010 3.2 GHz Intel Core I3 iMac slowed to a snails pace when editing the files in Adobe Lightroom.
There’s the issue of storage to factor in too. Shoot Raw files day in, day out with the A7R IV and it’ll culminate in your hard drive or cloud storage being quickly filled. If you don’t already have a suitable computer/storage system to deal with exceedingly high-resolution images, the A7R IV could require you to spend much more than the price of the body alone.