focus
Language: English
Part of speech: noun
Pronunciation: ipa: /ˈfəʊ.kəs/
ipa: /ˈfoʊ.kəs/
rhymes: -əʊkəs
Forms: form: foci
form: focuses
form: focusses
Etymology: Borrowed from Latin focus (“hearth, fireplace”); see there for more. Doublet of fuel.
Kepler introduced the term into mathematics and the sciences in describing elliptical orbits of planets (quote from Nicholas Mee) :
"One of the interesting properties of an ellipse is that if there were a light bulb at one focus, then all the light that it emits would reflect off the ellipse and converge at the other focus. This is why Kepler originally used the name focus for these points."
Senses: examples: text: The heat of sunlight at the focus of a magnifying glass can easily set dry leaves on fire.
topics: engineering
natural-sciences
optics
physical-sciences
physics
synonyms: focal point
glosses: A point at which reflected or refracted rays of light converge.
topics: geometry
mathematics
sciences
glosses: A point of a conic at which rays reflected from a curve or surface converge.
examples: text: Unfortunately, the license plate is out of focus in this image.
text: Not long ago, it was difficult to produce photographs of tiny creatures with every part in focus.[…]A photo processing technique called focus stacking has changed that. Developed as a tool to electronically combine the sharpest bits of multiple digital images, focus stacking is a boon to biologists seeking full focus on a micron scale.
ref: 2013 July-August, Catherine Clabby, “Focus on Everything”, in American Scientist:
topics: arts
broadcasting
cinematography
film
hobbies
lifestyle
media
photography
television
glosses: The fact of the convergence of light on the photographic medium.
examples: text: During this scene, the boy’s face shifts subtly from soft focus into sharp focus.
topics: arts
broadcasting
cinematography
film
hobbies
lifestyle
media
photography
television
glosses: The quality of the convergence of light on the photographic medium.
examples: text: I believe I can bring the high degree of focus required for this important job.
glosses: Concentration of attention.
examples: text: My studies are my main focus right now.
synonyms: focal point
glosses: Something to which activity, attention or interest is primarily directed.
examples: text: The earthquake's focus was at exactly 37 degrees north, 18 degrees south, seventy five meters below the ground.
topics: geography
geology
natural-sciences
seismology
glosses: The exact point of where an earthquake occurs, in three dimensions (underneath the epicentre).
examples: text: Text entered at the keyboard or pasted from a clipboard is sent to the component which currently has the focus.
topics: computing
engineering
graphical-user-interface
mathematics
natural-sciences
physical-sciences
sciences
glosses: The status of being the currently active element in a user interface, often indicated by a visual highlight.
topics: human-sciences
linguistics
sciences
glosses: The most important word or phrase in a sentence or passage, or the one that imparts information.
examples: text: Candles, in fact, are an essential ingredient in many spells. They can be used as either the focus of the spell or as a component that sets the spell's overall mood and tone.
ref: 2004, Marian Singer, Trish MacGregor, The Only Wiccan Spell Book You'll Ever Need:
glosses: An object used in casting a magic spell.
topics: biology
ichthyology
natural-sciences
zoology
glosses: The centre of an older fish's scale, which is the point where a younger fish's scale starts to grow from.
Derived terms: apofocus
autofocus
bifocus
cofocus
deep focus
focus-group
focus group
focus hunting
focus lamp
focus lantern
focusless
focus puller
hyperfocus
in focus
laser focus
long-focus lens
microfocus
nanofocus
out of focus
overfocus
perifocus
prefocus
pull-focus
retrofocus
self-focus
soft focus
underfocus
virtual focus