The Hartl Optical Disk is a compact apparatus that demonstrates the behavior of optical elements by means of ray paths through clear acrylic models. It consists of a circular 9” diameter graduated disk mounted on a stand and fitted with a ray box on an adjustable arm. Narrow, parallel rays of light are created across the surface of the disk by a cylindrical lens in the ray box and a pair of slit diaphragms placed in front of the lens.

The set includes six clear acrylic lenses and prisms with a magnetic backing that allows them to be attached to the disk in any suitable position, for use as optical element models. Includes activity guide.

The mounting of the disk allows it to be rotated through 360 degreees about an axis passing horizontally through its center to investigate the effect of angle variation on the ray paths through the optical element models.

The ray box requires a separately supplied power source capable of providing 12V/2A for the lamp.