Stemoto LogoStemoto
Back to Directory

Light, Shadows & Reflections (Smart Pinhole Camera & Ray Optics Analyzer)

Source:

Construct a digital Pinhole Camera (Camera Obscura) box! Project inverted images onto a translucent screen. A servo-aimed red laser beam reflects off a mirror onto LDR sensor targets, proving the Law of Reflection (Incident Angle = Reflected Angle).

Categorisation

Props & Materials Required

  • •Pinhole camera box with adjustable aperture discs
  • •Red laser pointer module mounted on SG90 micro servo arm
  • •KY-040 rotary angle encoder
  • •Acrylic mirror reflection stage with LDR sensor target array
  • •ESP32 controller board with 0.96-inch OLED screen
  • •DFPlayer Mini MP3 module + 3W speaker

Step-by-Step Instructions

1

Aim Pinhole Camera at Lighted Candle

Aim pinhole camera box at a candle target. Look at the translucent screen.

2

Observe Inverted Image

Candle flame image appears upside down on screen! Speaker: 'Light rays travel in straight lines and cross through the pinhole, inverting the image!'

3

Set Laser Incident Angle to 40 Degrees

Turn rotary knob to 40°. Servo aims laser at mirror at 40° angle.

4

LDR Sensor Verifies Reflection Angle

Reflected laser beam hits LDR sensor #4 positioned at exactly 40°! OLED displays '∠i = 40° | ∠r = 40° (LAW OF REFLECTION PROVED!)'.

Why It Works & Notes

Light travels in straight lines (rectilinear propagation). Passing light through a tiny pinhole creates an inverted image, while bouncing a laser off a mirror proves that Angle of Incidence equals Angle of Reflection (∠i = ∠r).