focal distance
focal length

The resulting higher quality of beam can be exploited either to obtain a smaller focus diameter or a larger focal distance.

This changes the focal distance of the eye so that it can focus on objects at various distances.

The first variable-focal-length lens with fixed back focal distance for 35 mm cameras, introduced in 1964.

The shorter flange focal distance may also allow for smaller, lighter and lower cost.

The smaller flange focal distance allows for more compact normal and wideangle lenses.

An object image is calculated at a given focal distance.

The difference of the focal distances is a constant.

The interchangeable backs allowed to insert the extension rings to compensate the difference in focal distance among the various lenses.

A recessed lens board effectively reduces the flange focal distance of a camera.

Lens mounts with shorter flange focal distances are longer and heavier.