Image sensors are used on Eternium-III for both the primary and secondary payloads. Two different physical cameras will be used on the satellite, because the secondary payload camera will likely make use of an optical filter that will block out important signal needed for the primary mission.
For the primary payload, the purpose of the camera is to take visible wavelength images of an amateur radio operator’s location.
For the secondary payload, the purpose of the camera is to take images at a very specific wavelength and try to detect a laser within the field of view. This laser will then be tracked, frame-by-frame, to try and detect changes in pointing of 0.1-0.2 degrees.