Q.5 a) How the defect in chromatic aberration can be corrected? b) Consider a lens made up of a material of refractive index 1.5 with a focal length 25 cm. Assuming h= 0.5 cm and q = 45°, obtain the spherical aberration and coma for the lens for various values of the shape factor q, and plot the variation in a manner similar to that shown in Fig. D Coma -2.0 -1.0 1.0 2.0 Q f -0.10 erical aberration Spherical -0.20 -0.30