Difference between revisions of "Subtense Angle"
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{{IALAFooter}} | {{IALAFooter}} | ||
See also [[Total Subtense]] | |||
{{languages|Subtense Angle}} | {{languages|Subtense Angle}} |
Latest revision as of 19:07, 8 July 2016
2-2-190
The angle, with vertex at the focus, subtended by the edges of a lens or reflector, usually measured in a horizontal or vertical plane. (Figs. 10 and 16b)
Note: In France, the subtense angle of an optical panel, measured in the horizontal plane, is called Ouverture.
In Germany, the subtense angle of a fixed lens or of an optical panel, measured in the horizontal plane, is called Spannwinkel.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
See also Total Subtense