focal length

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focal length

n. Abbr. f
The distance of a lens or mirror to its focal point. Also called focal distance, focus.

focal length


focal distance

(General Physics) the distance from the focal point of a lens or mirror to the reflecting surface of the mirror or the centre point of the lens

fo′cal length`

the distance from a focal point of a lens or mirror to the corresponding principal plane.
Also called fo′cal dis`tance.

fo·cal length

The distance from the surface of a lens or mirror to the point where the light rays converge to form an image (the point of focus).
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.focal length - the distance from a lens to its focusfocal length - the distance from a lens to its focus
distance - the property created by the space between two objects or points
ohnisková vzdálenost
distância focal
References in periodicals archive ?
I didn't realize that the entire experience of shooting with one lens gave me a lot of learning about focal length and how it would affect the image.
Although monocentric, orthoscopic, and Plossl eyepieces all provide decent eye relief, about 70% to 80% of their focal length, the short focal lengths required for planetary observing involve squinting through tiny eye lenses located a small fraction of an inch from your eye.
3: Experimental setup of Sony G camera with four lenses of different focal length and a chessboard pattern (1830 x 1330)
5 wide-angle lens, thinking that this will be closest to your own vision, consider this: the measured focal length of the eye isn't what determines the angle of view of human vision
It has a 30x zoom lens which in terms of focal length is 4.
This research indicates that the focal length of molded microlens acts as the goal.
One would expect that reducing the focal length of the objective lens in this manner would reduce the distance between the red and blue focus as a proportion of the cut off or remaining focal length of the objective lens over the short focus of the reducer, but not so
Folding the optic increases the effective focal length without increasing the distance from the front of the optic to the image sensor.
But as recently as 20 years ago the standard lens supplied with a 35mm camera had a fixed focal length of 50mm, which captured the scene being photographed pretty much as the eye saw it.
angle lens equivalent to a 24mm focal length or wider is absolutely essential for controlling perspective.
Questar's motorised StepZoom 180 is an 8:1 variable focal length lens with what the company describes as the longest focal length available in an optic of its size.
It was built in a mahogany housing for stability and had an adjustable width entrance slit, a 20-cm focal length quartz collimating lens, a Comu quartz prism, a 20-cm quartz camera lens and a plate holder for a 3.