Half-Silvered Mirror
Safety Warnings
Warning: Electrical Safety
Purpose
A half-silvered mirror simultaneously reflects and transmits light. By varying the lighting inside a box behind the mirror with a variac, a volunteer's reflection gradually transforms into a monster mask — demonstrating how relative intensity determines which image (reflected vs. transmitted) dominates.
Figure 1:
With interior lighting at full intensity, the half-silvered mirror primarily transmits light from inside the box, making the monster mask clearly visible while the reflected image of the observer is suppressed.
Figure 2:
At intermediate variac settings, both the transmitted image (monster mask) and the reflected image (observer) appear superimposed, demonstrating the beam splitter's simultaneous reflection and transmission properties.
Figure 3:
With interior lighting off, the half-silvered mirror acts primarily as a reflector, showing only the observer's reflection while the monster mask remains hidden in darkness behind the mirror.
Figure 4:
Interior view showing the monster mask and lighting arrangement. The variac-controlled lamps allow precise control of the relative intensities of transmitted versus reflected images.