Difference between revisions of "Subtense Angle"
Jump to navigation
Jump to search
Line 1: | Line 1: | ||
'''2-2-190 | '''2-2-190 | ||
Line 6: | Line 5: | ||
[[Image:Ch2_Fig10.jpg|400px]] | [[Image:Ch2_Fig10.jpg|400px]] | ||
[[Image: | [[Image:Ch2_Fig16b.jpg|400px]] | ||
Note: In France, the subtense angle of an optical panel, measured in the horizontal plane, is called Ouverture. | Note: In France, the subtense angle of an optical panel, measured in the horizontal plane, is called Ouverture. |
Revision as of 09:00, 1 March 2009
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)