FOCUSING
focalization, focalisation, focusing
(noun) the act of bringing into focus
focus, focusing, focussing, focal point, direction, centering
(noun) the concentration of attention or energy on something; “the focus of activity shifted to molecular biology”; “he had no direction in his life”
Source: WordNet® 3.1
Adjective
focusing (not comparable)
Used for or pertaining to focusing.
Noun
focusing (uncountable)
The action of the verb to focus.
Verb
focusing
present participle of focus.
Source: Wiktionary
FOCUS
Fo"cus, n.; pl. E. Focuses, L. Foci. Etym: [L. focus hearth,
fireplace; perh. akin to E. bake. Cf. Curfew, Fuel, Fusil the
firearm.]
1. (Opt.)
Definition: A point in which the rays of light meet, after being reflected
or refrcted, and at which the image is formed; as, the focus of a
lens or mirror.
2. (Geom.)
Definition: A point so related to a conic section and certain straight line
called the directrix that the ratio of the distace between any point
of the curve and the focus to the distance of the same point from the
directrix is constant.
Note: Thus, in the ellipse FGHKLM, A is the focus and CD the
directrix, when the ratios FA:FE, GA:GD, MA:MC, etc., are all equal.
So in the hyperbola, A is the focus and CD the directrix when the
ratio HA:HK is constant for all points of the curve; and in the
parabola, A is the focus and CD the directrix when the ratio BA:BC is
constant. In the ellipse this ratio is less than unity, in the
parabola equal to unity, and in the hyperbola greater than unity. The
ellipse and hyperbola have each two foci, and two corresponding
directrixes, and the parabola has one focus and one directrix. In the
ellipse the sum of the two lines from any point of the curve to the
two foci is constant; that is: AG+GB=AH+HB; and in the hyperbola the
difference of the corresponding lines is constant. The diameter which
passes through the foci of the ellipse is the major axis. The
diameter which being produced passes through the foci of the
hyperbola is the transverse axis. The middle point of the major or
the transverse axis is the center of the curve. Certain other curves,
as the lemniscate and the Cartesian ovals, have points called foci,
possessing properties similar to those of the foci of conic sections.
In an ellipse, rays of light coming from one focus, and reflected
from the curve, proceed in lines directed toward the other; in an
hyperbola, in lines directed from the other; in a parabola, rays from
the focus, after reflection at the curve, proceed in lines parallel
to the axis. Thus rays from A in the ellipse are reflected to B; rays
from A in the hyperbola are reflected toward L and M away from B.
3. A central point; a point of concentration. Aplanatic focus. (Opt.)
See under Aplanatic.
– Conjugate focus (Opt.), the focus for rays which have a sensible
divergence, as from a near object; -- so called because the positions
of the object and its image are interchangeable.
– Focus tube (Phys.), a vacuum tube for Roentgen rays in which the
cathode rays are focused upon the anticathode, for intensifying the
effect.
– Principal, or Solar, focus (Opt.), the focus for parallel rays.
Fo"cus, v. t. [imp. & p. p. Focused; p. pr. & vb. n. Focusing.]
Definition: To bring to a focus; to focalize; as, to focus a camera. R.
Hunt.
Source: Webster’s Unabridged Dictionary 1913 Edition