Figure 5: A recent example for the identification of the lensing galaxy in a double quasar system [43]: The left panel shows on infrared (J-band) observation of the two images of double quasar HE 1104-1825 ( = 2.316,  = 3.2 arcsec). The right panel obtained with some new deconvolution technique nicely reveals the lensing galaxy (at  = 1.66) between the quasar images. (Credits: European Southern Observatory [55].)