All Problems

Photometry and Geometrical Optics

Problem 5.32

An object is placed in front of convex surface of a glass plano-convex lens of thickness \(d=9.0 \mathrm{~cm} .\) The image of that object is formed on the plane surface of the lens serving as a screen. Find: (a) the transverse magnification if the curvature radius of the lens's convex surface is \(R=2.5 \mathrm{~cm} ;\) (b) the image illuminance if the luminance of the object is \(L\) \(=7700 \mathrm{~cd} / \mathrm{m}^{2}\) and the entrance aperture diameter of the lens is \(D=5.0 \mathrm{~mm} ;\) losses of light are negligible.

Reveal Answer
 5.32. (a) β=1d(n1)/nR=0.20; (b) E=πn2D2L/4d2==421x.\begin{aligned} \text { 5.32. (a) } \beta=1-d(n-1) / n R=-0.20 ; \text { (b) } E=\pi n^{2} D^{2} L / 4 d^{2}=\\ =421 \mathrm{x} . \end{aligned}