the plane that is perpendicular to the axis of a lens or mirror and passes through the focal point
2.
the plane in a telescope, camera, or other optical instrument in which a real image is in focus
Examples of 'focal plane' in a sentence
focal plane
Only the cells in the focal plane are illuminated, allowing noninvasive, extended viewing without "bleaching out" the sample.
The Scientist (2000)
For example, this scanning image cytometer captures images from several focal planes and automatically measures a variety of morphometricand intensity features of interphase cells.