Philips VarioFocus ensures optimal image resolution, by avoiding to compromise on which tube focus spot size to use, power load and exposure time. By using both focus spots simultaneously to define a variable focus spot, it automatically balances the power on both focus spots in a defined ratio, ensuring optimal image resolution at any required power. Tube filaments are preserved through power balancing on both focus spots and reduced power load on each of them, which may result in longer tube life.