QSO size ratios from multiband monitoring of a microlensing high-magnification event

The third phase of the monitoring programme with the 2 m Liverpool Robotic Telescope (LRT) began in 2010 October. This LQLM III project is being carried out with the RATCam CCD camera, the FRODOspec spectrometer and the RINGO2 polarimeter, so it represents a qualitative leap in our observational programme with the LRT. Moreover, new observations with the 10.4 m Gran Telescopio CANARIAS (GTC) are used to complement the LQLM database.