a) To build a spectrograph for the VLT that will cover simultaneously the wavelength range 300 to 1900 nm. This will be ideal for extinction studies and to probe the scale of lensing sub- structure using the method outlined by Moustakas & Metcalf (2003, MNRAS, 339, 607).
b) To investigate how VLBI methods can be used for lens surveys. The improved sensitivity of the EVN and the availability of high- speed computing can be exploited to make new very large lens surveys on angular scales that have not been probed before. We will make proof-of-concept observations.