He also liked the box cooker approach, which cooks food at a lower temperature, and does not require many realignments during the cooking period due to it's less focused reflector. He proposes an ellipsoidal shape reflector, that can be set at an angle to catch the sun for a longer period of time between adjustments. The shape catches the sun's curved path in the sky. The elliptical shape redirects less focused light on the cooker resulting in lower cooking temperatures.