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.



