Sony's newest full-frame mirrorless camera, the a7 IV, is the follow-up to the popular a7 III. Photographers using the E-mount system have been waiting for an upgrade for some time—the a7 III was our camera of the year back in 2018.
In the interim, Sony has rolled out new features in its higher-end models, upping the intelligence and performance of its autofocus system, adding support for new imaging formats, and leveraging faster memory cards for snappier response. It's also worked to refine ergonomics.
Updates to the Body
Many of these refinements have trickled down to the a7 IV. On the outside, its top controls are better thought out, with a flexible control dial doing more than the dedicated EV wheel it replaces, and a more accessible Record button, right behind the shutter release. The rear display gets a big update. Sony has opted for the swing-out, vari-angle style (just like its video-first a7S III), and uses a more modern 1.03 million dot touch panel.
The viewfinder is upgraded too; it's a 3.68 million dot OLED that can be set to refresh at 60 or 120fps. It's not Sony's biggest or sharpest, but should be a welcome update for a7 III owners—its viewfinder was recycled from the a7 II, and while fine for the time, isn't up to 2021 standards.
There's a new dial to switch between stills, video, and slow-motion (S&Q). The camera saves a separate bank of settings for each, welcome news for creators who swap between stills and video during the course of the day. You'll want to use different shutter speeds, picture profiles, and creative looks for different modes and represents a big step forward in usability.
New Sensor and Processor
The imaging engine is fresh too. The a7 IV leverages the Bionz XR processor (from the a7S III and a1) to drive its stabilized, full-frame sensor. The 33MP BSI sensor offers more pixels than others at similar prices, and supports more in-camera creative looks, as well as the standard JPG profiles. It also supports 10-bit HEIF and three types of Raw—uncompressed or lossless compressed at 14-bit, or compressed at 12-bit quality.
Creators have the flexibility to work in all types of light. The sensor can be set as low as ISO 50 for longer exposures in daylight, and goes all the way up to ISO 204800 in its extended range for low light work. Sony promises up to 15 stops of dynamic range, so Raw photographers should enjoy plenty of flexibility when editing images.
The autofocus spread is wide, covering all but the very outer edges of the frame. The wide spread makes the Real Time Tracking focus system work well. The Tracking focus follows moving subjects with tenacity, and is smart enough to jump on and lock on faces and eyes. The a7 IV supports eye detection for humans, many animals, and birds.
It's able to rattle off photos while it tracks, at up to 10fps. The drive speed is the same with the mechanical shutter or electronic one, but Sony has improved the buffer to handle more than 800 uncompressed Raw shots when paired with fast CFexpress memory. There are two card slots, one supports either CFexpress Type A or UHS-II SDXC, and the second works with SDXC memory only.
Flash metering has been improved too—if you're using an external flash the camera now checks exposure between each shot in burst mode, and leverages face detection for better TTL metering.
Video is now available at 10-bit quality internally, with 4:2:2 color sampling, and support for S-Log3 and S-Cinetone profiles. Full-frame width recording is an option at 4K24 or 4K30, the footage is oversampled at 7K so there's no binning or line skipping to compromise quality. 4K60 is an option too, but the angle of view is cropped to Super35mm, where the sensor matches 4K resolution pixel for pixel.
Autofocus is as strong for video as for stills—the camera tracks faces and eyes in the same way. The a7 IV adds a couple of assists for cinematography, including a depth of field mask to aid manual focus, and focus breathing correction for select Sony lenses. The feature works with many GM series lenses to eliminate changes in angle when racking focus.
It Costs More
The a7 III's introductory price, around $2,000, helped propel its popularity. The a7 IV is more expensive, around $2,500 as a body only, or $2,700 with a basic starter lens—in this case the aging FE 28-70mm F3.5-5.6. Canadian pricing is $3,200 CAD for the body and $3,400 CAD for the kit. The a7 III remains in market, it's selling for around $1,800 at press time, and the a7C ($1,800) is also still available as a lower-cost entry into Sony's full-frame system.
We'll have more to say about the a7 IV when we've had a chance to test and review it. Pre-orders will start tomorrow, with delivery anticipated in late December.