focal ratio

collocation in English

meaningsoffocalandratio

These words are often used together. Click on the links below to explore the meanings. Or,see other collocations withratio.
focal
adjective
uk
/ˈfəʊ.kəl/us
/ˈfoʊ.kəl/
central ...
See more atfocal
ratio
noun[C]
uk
/ˈreɪ.ʃi.əʊ/us
/ˈreɪ.ʃi.oʊ/
the relationship between two groups or amounts that expresses how much bigger one is than ...
See more atratio

(Definition offocalandratiofrom theCambridge English Dictionary© Cambridge University Press)

Examplesoffocal ratio

These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors.
In this study, the change infocalratiobetween juvenile and adult lungfish is calculated from frozen sections.
From theCambridge English Corpus
Even though the principles offocalratioare always the same, the application to which the principle is put can differ.
From
Wikipedia
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The focal length is 3.57 mm with afocalratioof 4.6.
From
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The primary mirror is a concave hyperboloid with 4.1 m diameter and about f/1focalratio.
From
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Two 48in cm concave metal mirrors were made for the telescope, each with afocalratioof f/10.
From
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It is the largest mirror of this shape and of such shortfocalratio; polishing it took 2 years, which was longer than anticipated.
From
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Today's anti-reflection coatings make these usable, economical choices for small to medium aperture telescopes withfocalratiof/6 or longer.
From
Wikipedia
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The "focal length" of the telescope objective is the diameter of the objective times thefocalratio.
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A 3 m secondary mirror produces an unobstructed field-of-view of 20 arcminutes in diameter with afocalratioof 15.
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The drawback is the system will have a highfocalratio, with a correspondingly dim image, and some vignetting.
From
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A highfocalratioalso means the field of view will be narrow.
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The focal length of 12.1 m combines with the baffled aperture of 3.7 m to afocalratioof 3.26.
From
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This is of particular importance in fish, where the value may decrease from as high as 3.6 to 2.3, decreasing thefocalratioof the lens.
From
Wikipedia
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On longerfocalratiotelescopes a well-made 90-degree prism diagonal is the optimum choice to deliver the highest image contrast short of using the telescope without a diagonal entirely.
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Wikipedia
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Newton's first version had a primary mirror diameter of 1.3 in and afocalratioof f/5.
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Wikipedia
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Newton's first compact reflecting telescope had a mirror diameter of 1.3 inches and afocalratioof f/5.
From
Wikipedia
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A re-calculation of spatial resolving power using measured focal ratios from cryosectioning reveals a low ability to discriminate fine detail.
From theCambridge English Corpus
Also, for fast focal ratios, the curve obtained is not sufficiently exact and requires additional hand correction.
From
Wikipedia
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The design is noted for allowing very fast focal ratios, while controlling coma and astigmatism.
From
Wikipedia
This example is from Wikipedia and may be reused under a CC BY-SA license.
These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors.
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Go to the definition offocal
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See other collocations withratio