Principle

In the experiments concerning combinations of lenses, the students' understanding of the light path through convex and concave lenses is both strengthened and extended. The first experiments serve as direct revisions, the experiments involving the combination of a planoconcave lens with a biconvex lens provide the opportunity for the students to understand that by using particular combinations of lenses and changing their distance of separetion, different total focal lengths can be achieved. At the same time, however, only qualitative statements are strived for.
Since the results obtained with a combination of a planoconvex lens with a planoconcave lens of the same curvature leads to a surprising result as far as the students are concerned, it offers a good starting point for a revision of the law of refraction.
The experiment is not so demanding in terms of the abilities and experimental skills required of the students. However, skills related to the careful adjustment of the experimental setup can be further developed. These are immediate prerequisites for the quantitative determination of focal length for lens combinations.

Benefits

• Multifunctional light box - All-in-one: Can be used for geometric optics on the table, colour mixing and on an optical bench
• Extension with others sets at anytime, no additional light sources needed, recognition value for students

Tasks

How does light travel through lens combinations? Investigate the course of light passing through a combination of convex and concave lenses.