A photosensitive media cartridge includes an ambient condition sensor mounted in the cartridge for sensing ambient conditions in the cartridge. When the cartridge is positioned at a media transfer position on an image-forming device that permits the conveyance of media from the cartridge to the image-forming device, image development or printing on the media in the image-forming device is controlled based on the sensed ambient conditions in the cartridge. The ambient condition sensor includes a cover layer and a conductive layer, wherein a rate of response to ambient conditions of the cover layer matches rate of response to ambient conditions of the photosensitive media to be developed. As a further option, the media itself can include a conductive layer so that the media can be the sensor.