Question

For a equiconvex thin lens with R-R, 20.0 cm and n, 1.500, use the Coddington shape factor to find a position p of a real object that will: a. minimize SA. b. minimize coma, Are your solutions unique?

Answer 1

Given that for a equi convex thin lens with R_1 = R_2 = 20.0 cm and n_r = 1.500 for the first surface, the object is placed at the image distance is n_1/s_0 + n_2/s_1 = n_2 - n_1/R sub 1 for n_1, 1.5 for n_2 8cm for s_0, and 20 cm for R in the above equation and solve for s_1 1/8 cm + 1.5 /s_1 = 1.5 - 1/-20 cm 1/8 cm + 1.5/s_1 = 1.5 - 1/-20cm 1/s_1 = 1/1.5(0.5/-20 cm - 1/8cm) 1/s_1 = -0.1 cm^-3 s_1 = -10cm therefore the image is famed due to first \r\n surface is at -10 cm, so the image is virtual 10cm left of the first vertex. Now acts as the object for the second surface the object distance for second surface is s_0 = s_1 + 5 cm = 15 cm the distance of the image that is formed due to second surface as follows n_2/s_0 + n_1/s_1 = n_2 - n_1/R the