I recently bought a DJI drone in order to get into the hobby of aerial photography.  The image sensor in my drone is called a "1/2.3 inch" sensor but it's actually 6.17mm by 4.55mm in size, which makes no sense at all. After a couple hours Googling I found this explanation:"Manufacturers of compact digital cameras have long used a rather ambiguous way to define the sizes of the sensors in their products. The system used dates back to video camera tubes used in the 1950s, with the 'inch' measurement referring to the outer diameter of the video tube. This system has no relationship to imager sizes and Photo Review endeavours to translate the 'type' measurement provided by camera manufacturers into millimetres to show readers just how small some digicam sensors are."[1]So why are digital image sensors STILL being named in reference to semi-arbitrary sized analog tubes?[1] 