A method for determining properties of a coating on a transparent film, a method for manufacturing a capacitor film and a device configured to determine properties of a coating on a transparent film are disclosed. In an embodiment a method includes moving the transparent film with the coating on a path which passes between a light source and a sensor, illuminating, by the light source, the coating on the transparent film, detecting, by the sensor, an intensity of transmitted light from the light source and calculating, by a processor, the properties of the coating on the transparent film based on the detected intensity of transmitted light.