🔎 Convex Lens — building the image with three rays

Three standard rays from the object tip fix the image. Move the object across the focus and the image flips from real and inverted to virtual and upright.

Walkthrough 1 / 5

Step 1 — the lens, its axis, the two focal points, and the object at distance u.

Object distance u 30 cm

Focal length f 15 cm

u = 30 cm · f = 15 cm · v = 30.0 cm
m = -1.00 · image is real, inverted

Animation speed 1.0×