A novel separation screen, a separation apparatus utilizing the separation screen, and a method for product separation are disclosed herein. The separation apparatus includes a housing defining a separation chamber having an inlet and a plurality of outlet orifices. A separation screen, which is located within the separation chamber, has a plurality of openings having fixed, non-uniform sizes. The separation apparatus also includes an adjustable feed placement device located upstream from the separation screen to direct a feed stream to a selected region of the separation screen to achieve a desired size distribution in each of the product streams.