physics chemistry


CONVERGING LENS - thin lens -

Focal length



Description: Interactive simulation to learn how to get an clear image of an object on a screen. Front focal point - back focal point - front focal length (distance) FFL - back focal length (distance) BFL - optical axis - focus - optical center



Converging lens: A converging lens focuses diverging or blurry light rays from a distant object by refracting (bending) the rays twice. Its curvature converts rays to a focal point behind the lens so that a sharper image can be seen or captured on a screen or camera sensor.

Focal point (principal focus): it is a point on to which light parallel to the axis is focused. Since light can pass through a lens in either direction, a lens has two focal points.

Focal length: distance from the lens principal plane to the focus.

Thin lens: thickness is very small compared to focal length.


flash animation