# Optical Images Of Lenses And Lenses Essay

A lens is an object that forms images by refracting light. The images formed can be magnified, real and virtual depending on what lens used and the set-up of the lens system. There are two types of lenses, converging and diverging lenses. Converging lenses cause parallel light rays to converge to a point. Diverging lenses cause parallel light rays to diverge. Typically converging lens are thicker in the middle and diverging lenses are thinner in the middle.

Lenses are used for many applications they are used in glasses to correct eyesight, cameras to focus and capture light to form images, telescopes and also magnifying glasses. The theory of lenses can be very complicated especially for multi lens system. However in the special case when the lenses used are “thin lenses” the theory to describe them can be simplified. A thin lens is one which has spherical faces and is relatively thin compared to the object and image distances. This type of lens has a distinctive point where all parallel light rays will converge called the focal point, f.

The main equations that are used in this experiment are the lens maker equation and the conjugate of foci equation (the lens equation).

The Lens Equation [1]

This equation was used in the analysis to find out the focal point of the lens used. This equation can be derived either by using geometry and trigonometry.

Figure 1 Ray diagram used to derive the thin lens equation

Figure 3 Ray diagram used to derive the thin lens…