Magnification
Purpose
Quantitative demonstration of thin lens magnification. A lens mounted above graph paper on a document camera magnifies the grid on the projected screen, where students measure the grid spacing with a meter stick to calculate \(M = h_i/h_o\). Comparing different lenses and object distances connects directly to the thin lens equation.
Figure 1:
The +150 mm lens magnifies the graph paper. A meter stick held against the screen allows direct measurement of the magnified grid spacing.
Figure 2:
Different lens position changes the magnification. Comparing measurements at different object distances demonstrates the thin lens equation.
Figure 3:
Apparatus setup: lens mounted in cross clamp on ring stand above the document camera. Graph paper is on the document camera deck below the lens.
Figure 4:
The +300 mm lens produces a different magnification than the +150 mm lens at the same object distance.
Figure 5:
Same +150 mm lens at a different height, showing how magnification changes with object distance.
Figure 6:
Side view of the setup showing a different lens in the cross clamp above the graph paper on the document camera.
Equipment
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