The beamsplitter allows the light path to be split allowing a video camera, digital camera, or an assistant head to be attached to the microscope. The most common beamsplitter used is a 50-50 / 20-80, which means one side splits the light into 50% to the users eye and 50% to the digital camera. The 20-80 is 20% to the camera and 80% to the users eye.