📷 Camera Obscura to Thin Lens: Pinhole Blur, F-Number, Depth of Field and Circle of Confusion

Build a camera from a pinhole to a thin lens. Move focal length, f-number and focus distance and watch the circle of confusion, depth-of-field slab, hyperfocal distance, diffraction limit and exposure change on a 3D set, with a simulated sensor image, a ray diagram and independent numerical checks.