collecting lens

Definition: Optics designed to collect energy and direct it into the rest of the system. * Usually an over-sized positive lens located at or close to an image plane e.g. collector lens for a projector or enlarger is placed next to the transparency or negative being projected. * It is over-sized to collect as much light as possible and to bundle them into the projection or enlarger lens. * Also 'collective lens' (US usage).

Previous Term: cold-light illumination  Next Term: collimated