Ray Optics / Lenses

See how a lens forms an image. Trace the principal rays through a converging or diverging lens and watch the image flip from real to virtual as you move the object.

Ray Optics / Lens StudioLive

thin-lens equation · ray tracing

Controls

Presets

Trace principal rays through a thin lens to locate the image. Move the object inside the focal point to flip from a real to a virtual image.

Focal length

Object distance

Object height

▶ Run in Python

Data Inspector

Lensconverging

Focal length120px

Magnification-1.00×

Equation1/v − 1/u = 1/f

Governing equation

\frac{1}{v} - \frac{1}{u} = \frac{1}{f} = \frac{1}{120}

Reading this result: The object sits near 2f, so the image is real, inverted and roughly the same size (1:1).

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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How it works

Using the thin-lens equation, 1/v − 1/u = 1/f, this tool traces the principal rays — parallel-then-through-focus and straight-through-center — to locate the image. Move the object inside the focal length to see a magnified, upright virtual image, or beyond it for a real, inverted one, exactly as in a physics lab.

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Frequently asked questions

Is this ray optics lens simulation tool really free?▾

Yes. Ray Optics / Lenses runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.

Do I need to install anything?▾

No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.

Can I save or share my simulation?▾

Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.

How accurate are the results?▾

The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.