Canon has only one ca file display screen.

What you want to ask is why Canon only displays screens in ca files? Shooting mode. According to the information of Pacific Computer Network, "CA" file is a shooting mode of Canon camera. Very suitable for some beginners, it is a very creative automatic function. People who have just learned to shoot can shoot faster in CA mode. Ordinary photographers can also use this function to adjust the brightness of images, and they can also blur the background in CA mode, which is very simple to use.