This is a small GUI for interactively modelling simple lens arrangements. Collimated and diverging rays are propagated through the lens system, where thin lenses are assumed throughout. If an real image is formed, its position and magnification are noted. An arbitrary number of lenses are supported, and may be added or removed interactively.
Click and drag to change lens focal lengths and positions.
Click the upper labels to manually alter distances, click the lower labels to manually alter focal lengths.