The ultimate answer of news photography

1 is confusing conceptually. There is no comparability between the two.

Continuous autofocus is mainly used to shoot moving objects, which will follow the moving objects in real time, and its high accuracy is certain. This concept mainly explains whether the focusing mode is once or repeatedly.

Area autofocus is to automatically select the focus in a certain area of the viewfinder, and of course there is also single-point autofocus. This concept mainly explains the selection method of focus, which has nothing to do with accuracy.

In the area autofocus mode, you can choose continuous autofocus or single autofocus. This makes it easier for you to understand.

2 Flash index is the value of ISO 100. If the aperture is changed, ISO cannot use 1/4.

The above is completely based on your own understanding! FYI