The Sony Alpha 7 IV, also known as the A7 IV, was announced today. The A7 IV is Sony's entry-level full-frame camera for 2018, replacing the A7 III.
The A7 IV attempts to be a true hybrid camera by improving both the photographic and video capabilities over its predecessors.
The new Exmor R CMOS sensor in the A7 IV measures 33 megapixels and is back-illuminated. With an ISO sensitivity range of 50-204,800, Sony's new sensor has dual native ISO, with ISO 3200 triggering the second step. However, the company does not advertise this. There are 15 stops of dynamic range, according to Sony.
Using the same BIONX XR image processor found in the Sony Alpha 1, the new sensor is coupled with that processor's latest generation. With AF/AE tracking and a larger buffer size than its predecessor, the camera can shoot continuously at 10 frames per second. the 759 phase-detection AF points provide fast, accurate autofocus tracking of moving objects, while the Eye AF system tracks moving subjects like people and birds in real time as well as tracking animals for the first time with a Sony camera.
The full width of the A7 IV's sensor can be used to capture 4K video. For all frame rates, including and below 30fps, the image is downsampled from 7K to 4K. The A7 IV, in contrast to the A7 III, is capable of recording 4K video at 60 frames per second. When shooting in Super 35mm mode, the image is cropped and does not utilize the entire sensor's width. Instead of 4:2:2 color sampling, the A7 IV records videos in full 10-bit depth with XAVC S-I intra-frame recording. Sony cinema cameras use the S-Cinetone picture profile, which this camera does as well.
Some of the new features are exclusive to the A7 IV and can only be used with a Sony E-mount lens when the camera is coupled with an E-mount lens from Sony. When using autofocus, the AF Assist mode supports focus transitions, and Focus Map uses colors on the screen to represent depth of field. In addition, Sony lenses with focus breathing issues now have a Breathing Compensation feature that crops the image slightly so that the field of view remains constant even if you move the focus from one end to the other.
A new top-layer mode dial for Auto/P/A/S/M and MR, as well as a lower-layer dial for Still/Movie/S&Q modes, have been incorporated into the camera's physical design for ease of use. To keep up with the times, the display has been completely redesigned with an articulating design that can be rotated. The resolution of the 3.68-million-dot EVF has been increased by 1.6 times. Dual card slots have been updated to support SD and CFexpress Type A cards in one and SD cards in the other. External recording and monitoring are now possible with the addition of a full-size HDMI port on the side. With the recording button now at the top, it's easier to use, and the magnesium alloy body has been enlarged for better grip.
Overall, the A7 IV is a vast improvement over the previous ones in terms of image quality and video capabilities. Purchasing the body-only version will cost you $2500, and it won't be available until December of that year. For an additional $2,700, Sony will offer a complete kit that includes the FE 28-70mm F3.5-5.6 OSS zoom lens.