Provided herein is a system for producing a product. The system generally comprises a large-area micro-stereolithography system, an optical imaging system, and a controller in communication with the large-area micro-stereolithography system and the optical imaging system. The large-area micro-stereolithography system is capable of generating the product by optically polymerizing successive layers of a curable resin at a build plane. The controller is capable of analyzing a focus level of the reference target based on the captured image; and based on the analyzing, adjusting a focus property of the projected image beam of the stereolithography system.