Difference between revisions of "Vertical Beam Divergence"
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[[Image:VerticalBeamDivergencePlot.jpg|none|frame|right|400px|figure 1]] | [[Image:VerticalBeamDivergencePlot.jpg|none|frame|right|400px|figure 1]] | ||
Note: In the past, lantern vertical divergence was defined as the angular separation of the upper and lower 10% intensity points in the intensity profile Full Width Tenth Maximum (FWTM). More recently, lantern divergence has been defined by the Full Width Half Maximum (FWHM) intensity, the angular separation of the upper and lower 50% intensity points in the intensity profile. | |||
Source: ENG7, Guideline G1065 | Source: ENG7, Guideline G1065 | ||
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[[Category:2.1 Optics and Vision]] | [[Category:2.1 Optics and Vision]] | ||
[[Category:Alphabetical Index]] | [[Category:Alphabetical Index]] | ||
[[Category:IALA Dictionary | [[Category:IALA Dictionary 2018 Revision]] | ||
[[Category:Approved by Council through approval of source document]] | [[Category:Approved by Council through approval of source document]] | ||
[[Category:IALA Dictionary 2023 Revision]] | |||
Latest revision as of 12:04, 4 February 2024
The angle of the light beam between points where the intensity has fallen to a fraction of the maximum intensity within the beam.
The vertical divergence is typically specified between the first points where the intensity falls to 50% of the maximum.
figure 1
Note: In the past, lantern vertical divergence was defined as the angular separation of the upper and lower 10% intensity points in the intensity profile Full Width Tenth Maximum (FWTM). More recently, lantern divergence has been defined by the Full Width Half Maximum (FWHM) intensity, the angular separation of the upper and lower 50% intensity points in the intensity profile.
Source: ENG7, Guideline G1065
