Optical Properties: Focal Length and Vergence

This section introduces fundamental concepts of lentilles convergentes et divergentes. The content explores focal length and vergence characteristics with detailed mathematical relationships.

Definition: Focal length (f') is the algebraic measurement of the distance between O and F', expressed in meters.

Highlight: For convergent lenses, F' is positioned after the lens (f' > 0), typically ranging from 0.080m to 1.5m, while for divergent lenses, F' is positioned before the lens (f' < 0).

Vocabulary: Vergence (C) represents a lens's ability to converge light beams, measured in diopters (m⁻¹).

The document also covers magnification (γ), defined as:

Formula: γ = A'B'/AB = OA'/OA

Example: When |γ| > 1, the image is larger than the object; when |γ| < 1, the image is smaller than the object.