An optical system for measuring an irregularly shaped object includes a dimensioning station having a base, a first wall extending from the base, and a second wall extending from the base. A collimated light is passed from each of first and second collimated light sources arranged generally parallel to the base, illuminating the first and second walls and defining first and second shadows, respectively. A camera is arranged to obtain image data representing each of the first and second shadows. The system is configured to collect the image data for determining at least one dimension of an object from each of the first and second shadows. Each of the first and second collimated light sources may be a light with a collimating lens arranged between the light and the respective wall. The light source may be an LED and the collimating lens may be a collimating Fresnel lens.