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: Features
The A7R IV is the first camera to showcase a 61-million-pixel back-illuminated full-frame sensor, with on-chip phase detection for autofocus. This sensor partners up with Sony’s latest-generation BIONZ X image processor and front-end LSI, with the aim of delivering unprecedented resolution, fine gradation and a 15-stop dynamic range at the low end of its ISO 100-32,000 (expandable to ISO 50-102,400) range. There have been a few rumours floating around that a forthcoming mirrorless camera (possibly the Nikon Z 8), might challenge the A7R IV’s resolution, however there has been no official word to say if there’s any truth in this so it remains purely speculation at present.
Despite an increase in resolution there’s no reduction in speed. It’ll happily shoot a continuous burst of 14-bit Raw files at 10fps for up to 7 seconds (up to 8fps in live-view continuous shooting mode) with full AF/AE tracking using its refined, low-vibration mechanical shutter or silent electronic shutter. Sony claims 68 images (Extra Fine JPEGs or compressed Raw files) can be shot in a single burst at 10fps, which increases to 200 when the A7R IV’s APS-C crop mode is used. We’ve seen APS-C/Super 35mm modes on an A7-series cameras before, but the A7R IV’s increase in resolution means you get a very useful 26.2MP output after cropping a full-frame image down to APS-C size. What’s more, the autofocus points remain in the same position as they are for full frame, resulting in a healthy 99% coverage across virtually the entire frame.
Out of APS-C crop mode there are 567 phase-detection AF points covering 99.7% height and 74% width of the image area. These are assisted by 425 contrast-detection AF points – the same number as you get on the A7R III. Sony’s 4D focus technology is available for sports and action photographers who don’t want to loose sight of erratic subjects. It uses special algorithms to detect fast action and predict your subject’s next move without getting distracted by obstacles in the frame. Sony’s Artificial Intelligence (AI) subject recognition technology also carries across, and for the first time on an A7-series model it can be used during recording video. You can select between animal or human Eye AF mode depending on your shooting situation, with precise focusing in low light down to -3EV.
Another first is the A7R IV’s wireless PC remote connectivity, which now supports wireless tethering for better freedom in the studio or out on location. Transfer of large uncompressed Raw images has been made faster too with a new algorithm for wired PC remote shooting. On the topic of professional features, pros who need to promptly deliver their images will also value the support of FTP background transfer during and after shooting. In total up to nine FTP servers can be assigned in advance.
Another feature the camera inherits from the A7R III is its 5-axis, in-body image stabilisation. As well as compensating for the common pitch and yaw movements, it adds corrections for movements of the camera vertically and sideways, with the fifth axis corresponding the rotational correction around the lens axis – crucial for movie shooting and ensuring high resolution handheld images remain pin sharp. The great thing about it is that it works with practically any lens and effectively allows users to shoot up to 5.5 stops slower than would otherwise be possible. Those who want to avoid shake caused by pressing the shutter button can trigger the camera wirelessly using a mobile device running Sony’s free Imaging Edge mobile app for Android and iOS. Alternatively, Sony’s RMT-P1BT wireless remote controller can be purchased for £65.
In addition to its impressive still image capabilities, the A7R IV offers a good, albeit not class-leading video spec. It provides 4K 30/24p video recording and full pixel readout without pixel binning in Super 35mm mode as well as S-Log 2 and S-Log 3 to maximise dynamic range and give videographers the control they need when colour grading during post processing. Full HD video at up to 120p is available too, although HDMI output is in 8-bit and there is no internal 10-bit support.
Touch tracking AF during video capture gives users the opportunity to pinpoint the subject they’d like the camera to focus on by simply tapping the screen. Audio quality hasn’t been overlooked either. As well as providing microphone and headphone inputs, which are now located behind the same cover, Sony has developed a state-of-the-art ECM-B1M shotgun microphone that connects via the camera’s Multi Interface Shoe. This has a digital signal processor (DSP) built-in for clearer sound recording and uses Sony’s noise-cancelling technology to rule out unwanted continuous noises.
The A7R IV rounds off its comprehensive set of features with Wi-fi and Bluetooth connectivity. Transferring single images or multiple shots to your device requires a single press of the Fn button during playback and the high-speed USB-C port at the side supports in-camera charging of the NP-FZ100 battery. This is rated to last for approximately 650 shots using the screen, or 530 using the electronic viewfinder.