Speed or resolution? 42-megapixel, 10 fps Sony a7R III mixes the best of both

The higher the resolution, the slower the camera — but Sony’s high-resolution a7R series is gaining a new shooter that defies that limitation by mixing a 42.4 megapixel full frame sensor with a 10 fps burst mode. Announced on Wednesday, October 25, the Sony a7R III has the same high resolution, but twice the burst speed, twice the autofocus speed, and even twice the battery life of its predecessor.

The Sony a7R III, like the A7R II, uses a 42.4-megapixel sensor without an optical low pass filter, but that sensor is upgraded with an improved on-chip lens design, anti-reflective coating, and new front-end microchip that works in conjunction with an upgraded Bionz X image processor to double processing speed. The new microlenses and coating improve light sensitivity, giving the A7R III a 15-stop dynamic range, according to Sony. The  camera also boasts a broad ISO range of 50-102,400 (expanded).

That faster processing speed allows the a7R III to shoot at 10 fps, double what the previous version could do. The only fine print is that, unlike the no-blackout Sony a9, Live View isn’t accessible at that speed and RAW files are limited to 12-bit. Other than that, the camera can fire away at full resolution with continuous autofocus while employing either the physical shutter or the quiet electronic shutter. Sony states the buffer will fill after 28 uncompressed RAW photos or 76 JPEGs.

A slightly slower 8 fps mode allows the electronic viewfinder to still display the image while shooting. Sony says several controls are still available while the camera is writing those large files to the memory card, including access to the menu and playback options.

A quick burst speed isn’t much good without a quick autofocus, but the a7R III is raising the bar there, too. Sony says the third body in the series can focus in low light in half the time as the previous model. The 399 phase detection points are still there, but now the 25 contrast detection points number 425. The additional points in the hybrid autofocus system creates that faster autofocus speed, while also delivering an accuracy of twice the predecessor. Eye AF is also improved, Sony says.

The updated sensor and processor has the Sony a7R III shooting 30 fps 4K video without pixel binning. The camera can shoot 4K in either full-frame or Super35 crop modes, but oversamples to 5K in Super35 for even sharper results. For advanced video shooters, a new Hybrid Log-Gamma feature supports HDR, along with expanding color grading options with S-Log2 and S-Log3. Stepping down the resolution allows the camera to shoot HD video at 120 fps for 4x to 5x slow motion, depending on playback framerate.

The a7R III also still includes the five-axis optical image stabilization system, with a rating of up to 5.5 stops of stabilization.

If the 42-megapixel resolution isn’t enough, the a7R III also includes a Pixel Shift Multi Shooting Mode. This feature capitalizes on the optical stabilization to shoot composites by shifting over in one-pixel increments four times, creating a 169.6 megapixel file, though photographers have to use the new Imaging Edge Software Suit, which is included with the camera, in order to stitch those files.

While both the sensor and processor get a refresh, Sony didn’t ignore the rest of the camera body either, introducing a number of new features geared towards professional shooters. The camera uses two SD card slots for storing all those high resolution bursts, with one slot supporting the higher speed UHS-II type.

While the series’ small body means a small battery life, Sony is doubling the specs there, too, with a battery with 2.2 times the capacity, allowing for about 530 shots using the viewfinder or 650 shooting with the LCD screen.

The A7R III’s body also boasts an even higher resolution electronic viewfinder with 3,685K dots along with a customizable frame rate of 60 or 120 fps. The LCD gets a boost, too, with a 1.44M dot resolution and a “WhiteMagic” design that Sony says improves viewing outdoors in bright sunlight.

While many of the controls remain the same, the a7R III adds a joystick control for selecting autofocus points. A new AF-ON and expanded touch focus also add to the expanded control options. The body is constructed from magnesium alloy with weather-sealing, and despite the larger battery and dual SD card slots, the camera weighs in at 1 pound and about seven ounces, only about an ounce heavier than the a7R II.

Connectivity options include Wi-Fi and Bluetooth along with a physical connection using a USB 3.1 Type-C port for tethering as well as a standard flash sync terminal.

The Sony a7R III creates a happy middle ground for the company’s mirrorless line, offering about half the speed of the Sony a9 but almost double the resolution at a lower price point. High resolution mixed with high speed is difficult to find, but the speed from the a7R III slightly edges the new Nikon D850’s 7 fps (9 fps with the battery grip), though the DSLR has a few more megapixels and doesn’t suffer viewfinder blackout.

Announced on the first day of the PDN PhotoPlus Expo in New York alongside an FE 24-105mm f/4 G OSS lens and the still-under-development FE 400mm f/2.8 GM OSS, the Sony a7R III begins shipping in November. The camera body retails for about $3,200.