The biggest differences between the a7C and the A7 III are in the body design of the camera. The a7C amazingly looks like the a6000 series camera from Sony, but it features a full-frame sensor and powerful features. It measures 4.9 inches x 2.8 inches x 2.2 inches at weighs 509g. It is much smaller than the a7C and weighs 22% less. Now, is that a good thing or a bad thing? It’s up to the user, many will prefer the robust feel of the A7 III, while those looking for an ultra-lightweight travel setup will enjoy the a7C design.
Although engineering is incredible, there are certain tradeoffs that need to be made when downsizing. There is no front control dial, only one custom button, no AE/AF lock button, and no AF joystick. Initial users are saying they prefer the handling and control of the A7 III versus the a7C, and the size/weight savings isn’t a large concern.
The viewfinder on the a7C is a 2.36million-dot XGA OLED, which is similar to the A7 III. However, it is smaller and lacks the same magnification power as the A7 III. The LCD is exactly the same as the A7 III, but it is fully articulating which is a nice addition.
The a7C also only features one SD card slot compared to the two SD slots available in the A7 III, which can be another big discerning feature between the two cameras for some photographers.