Định Nghĩa và Ý Nghĩa của "focal length"

What is "focal length"?

Focal length is the distance between the camera’s lens and the sensor or film when the lens is focused on a subject. It is measured in millimeters and determines how much of the scene is captured and how zoomed in or out the image will appear. A short focal length captures a wider view, making it useful for landscapes or large groups, while a long focal length zooms in on distant subjects, which is ideal for close-up details or wildlife photography.