A video display apparatus includes a cathode ray tube having an ultor terminal for developing an ultor voltage at the ultor terminal to produce a beam current. The ultor voltage has voltage fluctuations in a presence of changes in the beam. A resistive voltage divider is coupled to a source of a first high voltage and to a focus terminal of the cathode ray tube for producing at the focus terminal a second high voltage including voltage fluctuations. The voltage fluctuations are indicative of the voltage fluctuations of the ultor voltage to provide for focus voltage tracking. An amplifier responsive to a periodic correction signal is capacitively coupled via a capacitor having a value of 33 picofarad to the focus terminal. A dynamic focus voltage that varies, in accordance with a variation of a beam landing location, is produced at the focus terminals.