Thin Lens Concept

Demonstrations in Thin Lens

Five parallel light rays from a ray projector on the left passing through a biconcave (diverging) lens mounted on a magnetic board, diverging outward on the right side

Blackboard Optics Lenses

Uses a multiple-ray projector on a magnetic board to show ray behavior through converging and diverging lenses. Students see focal points, ray tracing rules, compound lens systems, and aberrations in …
Large convex lens clamped to a vertical rod on the lecture bench with a gray mounting plate, two illuminated desk lamps on a wooden stool positioned below
Safety

Convex Lens

Demonstrates real image formation with a convex lens and directly addresses the common misconception that different parts of a lens form different parts of the image. Blocking half the lens …
Lecture hall with translucent screen on left showing inverted real image of a glowing lamp filament, large convex lens on tripod in center, and boxed lamp visible in background right
Safety

Convex Lens and Lamp

A large convex lens (f = 220 cm) projects a real, inverted image of a lamp filament onto a screen. Students directly observe real image formation and can verify the …
Concave lens mounted on a post stand casting a circular shadow on a white screen, with a bright light source visible at the right edge

Concave Lens

Students observe that a concave (diverging) lens cannot form a real image on a screen, casting only a shadow. Holding the lens in front of your face shows students a …
Projected screen showing a +150 mm lens over magnified graph paper grid, with a meter stick held against the screen for measurement

Magnification

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 …
Diverging lens in circular mount on optical rail, with slide frame and colored ABCD card (A on red, B on green, C on yellow, D on blue) mounted on steel plate behind

Virtual Image

Demonstrates the fundamental difference between real and virtual images using a diverging lens. Students observe that a virtual image appears to occupy a definite location in space but cannot be …
Equipment layout on green table: teal variac, lamp in cylindrical housing on stand, box of aluminum foil, push pins on small foam block, and white poster board magneted to blackboard
Safety

Action of a Lens

Demonstrates the focusing action of a converging lens. Pinholes in aluminum foil each project a separate image of the lamp filament; placing a large lens in the path brings all …