Abstract: A payment acceptor (500) includes an inlet, a payment media transport path to transport payment media such as a banknote or a coin from the inlet to an interior of the payment acceptor, and an imaging sensor (501) to capture an image of an object inserted in the payment media transport path. The imaging sensor is configured to capture an image of a user (504) attempting to insert an object (505) into the inlet. At least one processor (3902) is configured to receive one or more images of the media captured by the imaging sensor via at least one of the one or more fiber optic sensors (1121, 1122), analyze at least one of the one or more images to determine at least one media characteristic of the media, store the at least one media characteristic in the memory (3904), and cause the payment acceptor to perform an action based on the at least one media characteristic.