Question

Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of smaller and smaller focal length and achieving greater and greater magnifying power?

Answer 1

Firstly, the process of making lenses with very short focal lengths (thick lenses) is not easy; secondly, as the focal length decreases, the defect of aberration in the lenses starts increasing. Due to this, the images formed by them become unclear. In reality, a single convex lens cannot achieve a magnification of more than 3, but a lens without an aberration defect can achieve a much higher magnification (about 10).