Focal length is the distance between the center of a lens and its focal point, while the focal point is the point where parallel light rays converge after passing through a lens.
Changing the focal length can affect the magnification and perspective of an image. A longer focal length can increase magnification and create a tighter field of view, while a shorter focal length can decrease magnification and create a wider field of view.
No, the focal length varies depending on the type and design of the lens. Prime lenses have a fixed focal length, while zoom lenses have a range of focal lengths.
Yes, the focal length can be measured in millimeters, centimeters, or inches. However, the most commonly used unit is millimeters.
The focal length can affect depth of field by changing the amount of background blur in an image. A longer focal length can create a shallower depth of field, while a shorter focal length can create a deeper depth of field.