Focal Plane (of a light)

2-2-170

The horizontal plane through the focus of the optical apparatus of the light.

Note: In lighthouse practice in some countries the term "focal plane" is used with the above meaning, although this is quite a different meaning from that of 2-2-165.

Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)

English

[[Category:2.2 Optical Apparatus]