f/1 — f/22 · Camera optics
How a camera lens works
How a piece of glass turns light into a photograph, from a hole in the wall to a blurred background. A 3D lens cutaway and ten figures you can play with.
Interactive explainers · videos
How things work. Turn the dial and see.
Raycat explains how everyday things work with live figures. You can turn every one of them yourself, and every explainer can also be watched with narration.
Focus · 50 mm f/2turn the ring
Explainers
About
Raycat is explanations you can touch. Instead of retelling physics in words, we build a model: rays, rings, scales. You turn it yourself and watch what happens.
Turn it yourself
Every parameter is a ring, like on a lens. Turn it and see what changes right away.
Honest physics
Rays, blur and angles are computed from formulas, not drawn by eye. Where a model is simplified, we say so.
A ginger cat
Every explainer has a cat: the model, the observer and the test subject. It brings physics down to earth.
- Nothing to installEverything runs in the browser, on a computer or a phone.
- Analytics with consentGoogle Analytics runs only if you allow it in the cookie notice. Fonts and scripts are served from our own server.
- Two languagesEnglish and Russian.
What should we explain next?
Tell us what you want to understand. The most requested topics become new explainers.