When shooting in Live View on the EOS 5D Mark IV, there are a variety of aspect ratio options available for your final image. The aspect ratio you select will affect the number of AF points and zones available. In 3:2, 4:3 and 16:9 there will be 63 AF points and 9 Zones. However, if you switch to 1:1 to create a square, you will have 49 AF points and 9 Zones. If you wish to keep access to the maximum number of AF points, then use any ration other than 1:1 and then crop your image afterwards on the computer.
- Camera settings
- EOS 5D Mark IV