Lens
See how a camera turns the world into a picture — and whose eyes it borrows. Change the lens to watch the field of view and perspective shift, open the aperture to control depth of field, and use tilt vs. lens-shift to keep a building's verticals straight — alongside a live plan diagram, a draughtsman overlay (horizon + vanishing points) and the real numbers (FOV, depth of field, hyperfocal). Eye-height presets (child / seated / adult / elevated) set the point of view, and Save frame exports captioned PNGs as storyboard seeds.
Runs entirely in your browser (WebGL via three.js) — nothing is uploaded. The optics use a thin-lens teaching model; bokeh shape is stylised and real lenses add aberrations, so treat the numbers as a clear approximation rather than a calibrated camera.