The design has been inspired by the CooKit, however using instead of a few reflecting panels, the Lightoven I incorporates many segments, which follow a parabolic curve on a reflecting bottom plate. The vertical focal line should ideally hit the cooking pot entirely. However when the angle of incident rays is not perpendicular to the reflector, the focal line tends to elongate. Reflector and cooking vessel are therefore designed in a way that all rays are reflected onto the cooking vessel - provided the sun elevation is at its geometrical optimum. The present design of the cooker is best suitable for medium elevation, i.e. the latitude of central Europe. The parabolic reflector can be tilted from vertical orientation by about 15° backwards to account for higher sun elevation angles.