An engraving depicting a Fresnel echelon or lighthouse lens from the front and side. At A is a plano-convex lens a foot in diameter surrounded by glass rings whose curvature is calculated so that they have the same focus as A. M, N are mirrors which turn light which escapes the lens into the same path as the primary beam. Dated 19th century.
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Details
Creative#:
TOP25359001
Source:
達志影像
Authorization Type:
RM
Release Information:
須由TPG 完整授權
Model Release:
No
Property Release:
No
Right to Privacy:
No
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