Compound microscope has two sets of lenses, the objective and the eyepiece. The basic principle behind it is to visualize the enlarged image of the object by the help of these lenses. When the beam of light passes through the object and then convex lense of objective, it forms a real inverted and enlarged image of the object in the focal plane of eyepiece (by adjustment). This image now acts as object for the eyepiece. Eyepiece lense finally forms a further enlarged virtual image of the object. Thus, magnifying power of a compound microscope is the multiplication product of magnifying powers of objective and eyepiece (Some=M0×Me).