Sony Alpha 7 IV
The Alpha 7 IV takes Sony's full-frame entry onto a new level – especially considering the much higher MSRP than before. The backside-illuminated 35mm sensor (Exmor R) now has a noticeably higher resolution of almost 33 instead of the previous 24 megapixels, and Sony has installed a fully-flexible touch display including a functioning touch menu.
The image processor is called BIONZ XR, is already known from the Alpha 7s III and offers significantly more processing power, which Sony uses, among other things, for a 4K video mode with up to 60 frames per second including internal recording in 10 bit with 4:2:2 sub-sampling. The camera can be permanently powered via a USB-C connection and used natively as a webcam on a PC or Mac (UVC Mode).
A small bottleneck remains with continuous shooting: The internal buffer can hold just 14 images, which at the maximum continuous shooting speed of 10 frames/s will last less than two seconds. With fast memory cards, however, much longer sequenzes can be realized, whereby with the compressed JPEG or HEIF format it is generally possible to shoot longer without interruption or slow-down.
CFexpress or SD Memory Cards?
The Sony A7 IV has two memory card slots. The first compartment can hold either an SD memory card (UHS-II support) or a CFexpress type A memory card. The second compartment is exclusively for SD memory cards, also with support for fast UHS-II models. The larger type B CFexpress memory cards used by almost all other camera manufacturers are not compatible.
Probably thanks to the still fairly new BIONZ XR image processor, the Sony A7 IV achieves an impressive 245 MB/s with UHS-II-capable SD memory cards. However, the comparatively large files are responsible for, especially shooting RAW, a more or less severe speed decreases after a few seconds. Only CFexpress memory cards allow almost unlimited continuous shooting. Unfortunately, the Type A format is only supported by a few manufacturers, is very expensive and currently offered with a maximum capacity of just 160 GB.
For 4K video recordings, speed class U3/V30 or higher is mandatory – corresponding SD cards are marked with a label. For slow-motion and all-intra recordings (XAVC S-I), Sony even requires class V90, which we mark with an label.