focal points
1focal point — focal points N COUNT The focal point of something is the thing that people concentrate on or pay most attention to. ...the focal point for the town s many visitors the Royal Shakespeare Theatre …
2Focal length — The focal length of an optical system is a measure of how strongly it converges (focuses) or diverges (diffuses) light. A system with a shorter focal length has greater optical power than one with a long focal length. Thin lens approximation For… …
3Focal cloud — A focal cloud is the collection of focal points of any imperfect lens,whether optical, electrostatic or electromagnetic. This includes Parabolic antennas and lens type reflective antennas of all kinds.In this focal cloud illustration, a perfect… …
4focal point — UK / US noun [countable, usually singular] Word forms focal point : singular focal point plural focal points 1) the most important, interesting, or attractive part of something, that you concentrate on or pay particular attention to The focal… …
5focal length — noun The distance at which something (e.g. a lens, mirror etc.) is in focus; in air it is the distance along the optical axis from a principal plane of the lens to one of the lenss focal points …
6Focal surface — For a surface in three dimension the focal surface, surface of centers or evolute is formed by taking the centers of the curvature spheres, which are the tangential spheres whose radii are the reciprocals of one of the principal curvatures at the …
7focal adhesions — Areas of close apposition, and thus presumably anchorage points, of the plasma membrane of a fibroblast (for example) to the substratum over which it is moving. Usually 1 x 0.2 m m with the long axis parallel to the direction of movement; always… …
8focal point — 1. Also called principal focus. Optics. either of two points on the axis of a mirror, lens, or other optical system, one point being such that rays diverging from it are deviated parallel to the axis upon refraction or reflection by the system… …
9focal point — fo′cal point n. 1) opt either of two points on the axis of a mirror, lens, or other optical system, on which rays converge or from which they deviate 2) the center of activity or attention 3) the central or principal point of focus • Etymology:… …
10Affine focal set — In mathematics, and especially affine differential geometry, the affine focal set of a smooth submanifold M embedded in a smooth manifold N is the caustic generated by the affine normal lines. It can be realised as the bifurcation set of a… …
